Lessee...I'm not sure if these opinions are unpopular, per se, but they certainly aren't shouted with death threats attached as much as their opposites, so I think it counts.
NTR is fine.
It's perfectly OK if every game has incest, especially games where it's one main PC in a house with everyone else he has sex with.
Devs should basically never listen to their fans when it comes to what actually goes in their games.
Adding traps/herms/etc. makes a game gay. That's probably also true if the main character is female. It's perfectly fine if you want your game to be a gay game, but your game is no longer completely heterosexual if you start adding traps to bang, and a heterosexual player is justified in questioning whether your game will still be something they are into once you start developing in that direction.
A person can stop supporting a game at any time and for any reason, not just for reasons that some random person on the Internet views as justifiable. Those reasons can be real or imaginary, that shit doesn't matter. No dev has a perpetual right to your wallet.
Gameplay is good. Even if the gameplay isn't great, it's generally still better that there be some gameplay rather than none. An example of a type of game with essentially no gameplay is a visual novel.
Visual novels, with very few exceptions, are bad and lazy. I realize that they're many devs' introduction to making video games, but if so, those devs should release those test games for free rather than acting like any work they ever put into anything is solid gold and always worth money. When you make art, sometimes you make practice art that won't sell.
It's more important that a game be interesting rather than good.
Corrollary: a game referencing a certain former president of the US is not automatically interesting as a result of that reference.
Titties that would be uncomfortably large on a real woman are A-okay in porn. In fact, unrealistic proportions and actions and even outright immoral activities are perfectly fine in fictional porn games, though not every player has to enjoy them.
To quote Ferris Bueller: "You can never go too far." That definitely follows for the fetishes represented in a game. Again, the main limiting factor should be what people are willing to support, not some concept of morality generally applied to ordinary IRL interactions.
Judging people by the porn they like is dumb and always makes the person doing the judging an asshole, full stop. You like what you like, and you don't get a choice about it. Otherwise, gay conversion camps would actually work instead of just being child abuse and a way to meet other gay kids abused by homophobic Christian parents.
