Biased opinion that seems wrong. It becomes a pretty popular addition and it seems like it gathers some additional funds. No project lost its patrons due to addition of it. Moreover, devs like saddoggames or Daniels K have grown significantly after open addition. One game already reached SS territory that was mostly NTR when it reached it that we all know. You can despise it but there is a large gap between not being a fan and despise something. I doubt most people strongly care about it and it might gather additional people as it works strongly on emotions.
You can also lose your existing fans and patrons because of this. A number of people aren't playing Big Brother anymore because of the whole Eric thing. Sure, you can mod him out, but I for one didn't want to bother after a certain point. And I know a number of other people that no longer play Big Brother for the same reason. So the question is, do you want to abandon a number of your current fans for the new ones?
And as for people not caring, there have been numerous flame wars on this forum about NTR, and the moderators have stepped in on numerous occasions to shut down such flame wars. So I disagree with your assumption that most people don't care strongly about it.
The one thing that ties together ALL OF the Popular games on this forum right now? Incest.
Big Brother - Incest
DMD (formerly Dating My Daughter) - Incest
Dreaming Of Dana - Incest
Dreams Of Desire - Incest
My New Life - Incest (at least that's what the tags tell me)
Son Of A Bitch - Incest (again, what the tags tell me. This download is waaaay too huge, which is why I've passed on it)
Summertime Saga - Incest
Super Powered - Incest (again, that's what the tags tell me, and the MC does live with his Mom apparently).
Teacher's Pets - Incest (although Irredeemable is in the midst of modding that out to appease Patreon)
The Twist - Incest (haven't played, but it's pretty clear that there is incest going on based on post #5).
That's 10 out of 10 games that have the incest tag. And at least one of those doesn't have NTR at the moment (Teacher's Pets).
btw, it appears that a game becomes popular on F95 once a game has more than 100 pages of posts