That doesn't really compare though. Sure, plenty more people will see the beginning of the game than the end. On the other hand, it's conceptually impossible to not have an end to the game (even if you'd want to). Romances are entirely optional, however.
As for the conditional dialogue options, those will indeed be seen by only a subset of players. But these are very minor, they generally add flavour and maybe a small change in gameplay (you resolve a confrontation peacefully instead of fighting, you get an item) but not much else; they're mostly very self-contained, different branches of dialogue will quickly converge back onto a finite set of outcomes. The choices you made in this regard usually have no impact on the rest of the game (except through generic mechanisms like dispositions and reputation and such). This makes them attractive from a development point of view, because the investment is typically just a couple of lines of dialogue being added, some differences in the quest log and whatnot. There will be exceptions to some degree, NPC-specific quests are inherently an example of that as well, but the degree to which such kind of content is included definitely has to be weighed against its cost. And given the sketchy track-record of romances in RPGs and games in general and the fact that its appeal is rather more limited than general NPC quests and content, there are plenty of good arguments against including them.
As for player choice, I don't really see how romances in themselves really add to that. They offer the choice of pursuing the romance or not, but then again that applies to any content; I can choose to do the NPC quests or not, I can choose to do any of the optional side-quests or not. It gets you stuff and experience points, but by themselves they can still be entirely linear. Romances in games generally are fairly as well, so in that regard they don't offer a clear added value above more general optional (NPC-specific or otherwise) quests. And of course you can make a more branching romance, but the same applies to any other quest or content as well.
They don't have to be about money and business sense alone, in my experience it works out better if the people making it can be creative and put something of themselves into it. But money is the bottom line, it's what makes it possible to make the game in the first place. And in a more general sense, money and successful games are what makes it possible for a compaby to continue to make games.
This equation doesn't change because of Kickstarter backing, there is still a finite amount of money which can be converted into a finite amount of game content. It will tend to result in backers influencing that content, but that should only go so far; it's not a democracy, it's up to the developers to make the decisions and try to make it a good game. Besides, I'm not so sure such a large proportion of backers would consider romances all that crucial anyway.
Moreover, the equation still doesn't change when a game is being developed by a single individual. It still takes time and money to do so, and it's hardly guaranteed to result in a better game if there's one person making all the decisions for it. It's no different from any other creative medium, most of the things people create are mediocre at best; because it takes talent and imagination and practice and a lot of work to make something that's actually good. A random dude making a game in his spare time having all those qualities... the odds are fairly bleak on that. And even if he does manage to pull it of, what makes you think that game *will* contain extensively branching content (it won't) or romances?
I'm also not sure what you're basing the notion on that the dislike of, or opposition to, romances in games/RPGs is due to a prejudice to specific elements of human nature like romance. There are lots of other aspects of human nature that don't get much attention in games either. You don't see a lot of pooing in games either, and I'd say that's far more fundamental to human existence than romance (and far more relevant to warfare as well). Mostly, these are things that are just not very central to the reasons people play the game in the first place, and including them would be more effort than it's worth.
I agree that games take imagination, time, and dedication. However, there are tons of games made by people in their free time with branching paths--or, at the least, with choices and consequences: http://www.gamesradar.com/10-games-developed-entirely-one-person/ , https://www.quora.com/What-are-the-best-games-designed-and-built-by-only-one-person
I'm basing "the notion [ . . . ] that the dislike of, or opposition to, romances in games/RPGs is due to a prejudice to specific elements of human nature like romance" on posts like the one Nonek made, but I realize now that I was being hasty. Hatred for romance topics on forums seems more-so to be a dislike for people like me, rather than for a specific aspect of human nature.
It makes sense that a lot of aspects of human nature don't get talked about in video games. But there are games about cancer (http://www.thatdragoncancer.com/#home), games about feces (http://store.steampowered.com/app/449540/), and games that aren't scripted in a traditional, linear manner (https://www.youtube.com/watch?v=NoUKgEuskMs). I think it's a bit unfair to say that "these are things that are just not very central to the reasons people play the game in the first place," because there seems to be a demand for these games; they seem to be filling a void in story-telling and/or interaction that couldn't be achieved through a novel or some other medium. But if you're talking specifically about PoE, then I see your point and have to agree that people have myriad other reasons to play the game than the reasons I've talked about. In fact, I'm a bit anxious that my original post might not have been on-topic for this section of the forum because I think I'm more-so talking about games in general rather than PoE specifically.
Well that escalated quickly :-P Yes, it's true, many RPGs, PoE including, are built on the premise of content changing and adjusting based on player choice. Most of the time however, content can be reused and reshuffled as needed in order to maximize feeling of player impact while minimizing work necessary to achieve such end. If you wrote a fully fledged romance however, we're basically talking a huge dead branch of vastly different content which can't really be used anywhere else - I'd prefer that effort going into fleshing out the non-romance aspects of a companion.
I'm sorry about that. I meant to use the question as a rhetorical device, but now I see that my response was heavy-handed and extremely rude. I'll try to be more careful.