Vocal minority, really. Even at it's peak the amount of people who took issue with it were small in comparison those who liked it or remained indifferent, and even now those same people are the ones that get involved here.
I have a BA in a design field, I know all about dumping many hours into a doomed project, and in that regards I agree that time does not equate quality. The favored description amongst professors was "polishing a turd." Doesn't matter how much effort you put into it a turd is still a turd. A bad base leads to a bad finish. The thing I was addressing when pointing out my frustrations is there are more than a few instances where legitimate criticism is thrown to the wind in favor of boiling everything down to a deliberate targeted attack against a portion of the player base, especially when terms like "character assassination" are being thrown around. That's bad faith and unfair to the author, quality of the content be damned. I am not saying that it's the only thing people are doing, but it's certainly been done enough to notice.
And that still doesn't change the fact that it's the same arguments every time and most of us just wanna move on from it and be able to at least mention the character without risking this get resparked for the nth time.
Sure, but throwing any sort of negative discourse in to the bin because "it is same old same ol'' is just disingenuous to people that are genuinely not happy with how it all turned out.
But if you want some more defined criticism of the expansion, well:
The parsers make it pain in the ass to write for Berwyn which means that one of the goals --making it easier to support him -- failed. It introduced a problem that his past self did not suffer from. Which is how this whole discussion started at first place since someone asked for content of Wynne and Matiha and they got struck down "it would be to hard."
It takes away focus from Berwyn and what made him him and spreads it to thin; especially compared to his past content which I believe is genuinely better written and shows more of that bratty charm than what his expansion self can match.
It removes content, full stop. Especially his pregnancy content.
More personal ones:
When playing as a vagina champ, it does feel little odd that I can not top him by power-bottoming
Matiha is boring and if you have no interest
In her, you do lose on a lot of content.
Sure, s/he is more popular, but counter point -- any guy would be more popular if you could turn him into a girl since that is what most of the audience wants. And popularity really means little to me since that it doesn't really tell you if something is good or bad.
Having a character that I liked be twisted for the sake of masses is not something that I am a fan off.