Because as a genre is has quite a few haters. Personally I am just as bored with the same big dick shota + mother + 2 sisters genre that's copy-pasted as well. They are similar in how much potential they are wasting. Both betrayal (ntr) and incest are juicy subjects that can make for really interesting stories. But most devs ignore that and just make the same game.
Oh, I know. NTR made them feel bad and now they need to let everyone know.
Sounds a lot like western games and incest harems.
Eh. I just take it as it goes. The genre itself is likely enough for me to like it (unless it's basically a scene finder). And if it's better than what I thought, it's a welcome surprise. Plus I'm not paying for this stuff so I can't be
too upset about it either.
I think it's more so they're frankly not creative enough to make something interesting and if they are ignoring it, it's not consciously. They see what's popular and it's easy money. NTR is a bit of a trending fetish afterall.
There are plenty of manga and webnovels that deal with cheating in more interesting ways but hentai always sticks to same scenes, same story, same ending.
I've already said my thoughts on that matter in my last post so I don't think we need to stay on that topic any longer since I'm sure we agree to disagree.
I'm only really familiar with douj, so if you've got any good recs outside of that, let me know.