Your feat example is in fact, an example of a rather tame bug. I'm not wanting to defend Obsidian here because I agree they need to improve on this, and we should be setting our sights high... but it wasn't a case of Obsidian being markedly inferior to other RPGs in terms of bugs.
Morrowind? Oh dear God, so many people could not play it for weeks after launch. Bethesda got better and FO3 was a remarkably stable game for its size, though.
Play Gothic 3 and you will understand the meaning of 'playable'. It froze every 60 seconds, took longer to save & load than for you to drink a cuppa, etc.
All Troika Games, obviously, need a mention.
Bio's become pretty good with this with Jade Empire and Mass Effect, so that people have forgotten about the aberration that was NWN1 (as bad as 2, really.)
I don't think Obsidian has a fatal reputation for being buggy, but it is certainly seen as below the standard on that area.
I could have choose a whole host of other bugs, But i chose the missing Feats because i feel this bug mostly describes the state NWN2 is in.
Imagine that - making NPC characters, Design them, Discuss them with your coworkers ..and then "forget" to give them the right Feats, i Mean in NWN2 you could just as well forget to give them arms or legs, Espeassialy since it is so unbeliverble easy to assign Feats.