It seems that you haven't understood some mechanics correctly.
1. [For example the Dragon Thrashed chant is a DoT effect that doesn't have to overcome the full DR. It's also stackable with itself - which means that at higher levels (due to Brisk Recitation and high INT) three instances can be stacked at a time. That means that 60 base damage get applied every 3 seconds, more with a crit (10 base slash + 10 base burn per 3 sec). Add high MIG and you can see where this is going and why it "melts" enemies. On normal or hard most foes will be dead before a rogue can kill three of them. On PotD it's even better because there are more enemies and they all get hit at once. More enemies is meaningless for the Chanter because he hits them all. It has to do an attack roll and thus can also crit. It is not awesome against bosses, but not bad. I mean you deal lots of damage passively - that's quite awesome.]
2. [Also your perception of the cipher deviates a lot from what most people here think about them. First of all they can achieve similar single target damage as a rogue with auto-attacks (Soul Whip + Biting Whip) whithout the need for afflictions - which is awesome for a caster. Then a cipher is unmatched when it comes to mind control which is the most powerful crowd control mechanic in the game. Ask the dragons...]
3. [If you think the monk is bad you simply didn't understand how he plays. After playing several playthroughs with all classes and after countless testing session and also solo runs I believe that the monk is the strongest melee class in the game overall - from the beginning of the game till the end - if you handle him correctly. But needs a lot more micromanagement - more like a caster. He's also one of the best ranged dps classes in the game (from lvl 7 on). I'd say THE best ranged class. He can have awesome single target damage via lashes, very good AoE damage, very solid defenses, great starting values, some very potent single target CC options and a very big endurance and health pool. There's a reason why most players fear high level enemy monks - but enemy rogues? Not so much.
You also didn't seem to understand that a monk can use any weapon with all his abilities. He's not restricted to fists in any way, but they are a good alternative to weapons.
It sounds as if you didn't really play one. How can you say a monk is bad if you didn't play him?]
4. [The rogue is especially weak on PotD - but even on the other difficulties he's not top notch. And at higher levels the "ultimate CC effect aka death" takes some time to get applied. Especially once the rogue lies flat on his face again.]
5. [I guess if you'd do a poll in this forum then most people would say that priest is the most powerful/impactful class, followed by wizard/druid.]
6. [By the way: two handers have the same attack speed and recovery as swords/maces/spears (all the heavier one handed weapons). Dual wielding and every other speed bonus except DEX only affects recovery time. So once you can achieve 0 recovery with a two hander it's the better dps option (except with Full Attacks of course). It's way easier to achieve 0 recovery when dual wielding. Especially from early to mid game dual wielding is superior in most cases.
But some mechanics favor two handers over DW (abilities with primary attack & Blood Thirst for example).]
Dps wise the best auto-attack option for rogues are fast one handers for the most part of the game. The melee weapon with the best dps in the game is Drawn in Spring if you are not at 0 recovery. Great weapon for a rogue. Once you can hit 0 with a two hander then then best dps weapon is Tidefall.
7. [Single target interrupts become less important if you have other good CC options and if you are fighting a lot of enemies.]
I bracketed out your points so they would be easier to reply to, I hope you don't mind.
1. Oh I totally get it- btw didn't know it still had to make an attack roll, that's less awesome even than I thought, so I was actually overestimating it. However please keep in mind that before it stacks up to 3x, he has to have chanted into his 3rd phrase, which means you're at least 15 seconds into combat. So you do 6.67 dps, then 13.3, then 20, building up. And that's before DR, which still applies in some way shape or form (it's not RAW damage after all). Yes it's AOE and yes it's passive and on top of whatever you're actually doing. But when fights are over before 15 seconds comes around, you can see how it would be unimpressive. Great PotD ability. Like most of the chanter's kit, way too slow for anything else.
2. Meh. Mind control is able to be talented into, and indeed it's the best part of his kit. Otherwise (personal impressions) he's like the Chanter, too slow to build up to be really powerful in non-boss fights, unable to continuously unload like traditional casters in boss fights. If all my enemies are knocked down, blinded, and / or dead before he gets out his 2nd spell, what does it even matter what that spell is? Again I get that in PotD he would be more useful, since he basically generates additional per rest level abilities the longer the fight goes. So the more drawn out it is, the more competitive he is with traditional casters. Also his damage comes nowhere close to a Rogue. Even assuming you're not investing heavily in Intellect for longer mind control duration, he maxes at around 50% bonus damage whereas a Rogue is doing 150% consistently. And it's not like applying debuffs like knocked down or blinded is such a burden anyway, action denial and debuffs are always helpful to everyone.
3. I don't take damage. Typically, in non-boss fights. In boss fights, on average 3 people take damage (1 minor, 2 major), from the boss, before I can finish clearing all adds and lock him down. The requirement to take damage to power up is excessively onerous under those conditions. You are indeed correct in that Monk is the only class I haven't had personal experience with- haven't bothered yet, my party does not feel lacking, and what it does lack he does not have in his kit. I will absolutely eventually try him, and maybe my opinion will change drastically. More likely, I will feel like the reason I'm taking damage all the time, and therefore the reason I'm getting value out of him, is because I have a monk in my party instead of a better character who could help me avoid taking damage in the first place. Due to lack of personal experience I can say that I absolutely could be 100% wrong about this.
4. I dealt with that in another reply to you (which with my time delay is further up, sorry again for that), but I mean if he was SO useless why have him around at all? For me, on hard, I find the damage to be insane, and given a situation with the chanter, if they are both against 3, the Chanter will be doing his mild AOE damage which can ramp to something useful around the time the Rogue has finished killing 2 of them and is hacking away at the 3rd denying any actions at all to him. I get that PotD is different but to claim it's anything other than 2nd tier on lower difficulties seems disingenuous. Top tier being of course the primary casters, we can certainly agree the ability to blow as many per rest abilities as you want, and rest at will, makes them the most powerful option if you don't mind resting as needed.
5. Sure, on PotD. Long drawn out engagements with lessened ability to CC and more facetanking puts a premium on healing. Makes sense. Buffs last for quite a while and can hit every party member, while debuffs tend to last shorter times, can be resisted, and are against a limited number of enemies, also having to work around immunities. I can certainly see how that would be true.
Can you in turn see that debuffs, if able to be consistently applied, are instead more powerful? If you actually can blind / knock down / interrupt everyone, and pursue an effective strategy of action denial, it doesn't matter how strong the enemy is or how weak you are, they will do nothing and you can kill them at your liesure with zero risk or damage taken, which means there's absolutely zero value to healing.
6. See my reply to Abbzug above, it's not about the DPS, even if 2h were way superior it'd still be an inferior option imho due to interrupts.
7. I'm going to just respectfully disagree on this one. Every single weapon in the game, in addition to its other attributes, has "deals (interrupt duration) stun on hit, interrupt vs concentration". You have an at will stun usable by all characters at a rate of potentially over 1/second. If you have enough CC for that to not have value, then you have enough CC for nothing else to matter, and then Priests shouldn't be good since every enemy is so CC'd you never take damage anyway. If you take damage, that means enemies get actions off, which means you failed to have enough CC to cover everything.
Which brings me to kinda my whole theme here- in all the advice I see, people talk like everyone's playing on PotD, and the action economy game is just unwinnable and not worth engaging in, and every fight is going to be a minute long slog or more. If people are not playing on PotD, I feel like it would be very helpful for them to know and understand the concepts behind managing an action economy, and why Mind Control is the best debuff in the game (better than death, even, in some ways, because in addition to denying all actions from that character for the duration you actually gain actions on your side), and how the best way for you to easily win fights is to ensure you have as many useful, meaningful actions you can engage in on your side, while they have as few, and as ineffectual, of actions possible on their side. This is universally true in virtually all games, but especially in turn based games or games like PoE.
This is exactly why the Chanter's AoE is so good on PotD, he gets a "free" "attack" against all foes in his AoE radius every 3 seconds, stacking up over time, which over a long fight is a LOT of free actions. In the exact same circumstances, the "free" attacks granted by the Barb, which tick much more often (not only accuring free actions faster, but also denying more enemy actions) should offer as much or more value, not necessarily in terms of damage done, but in terms of how much he sways the tide of the action economy of each side, respectively.