What non-sexual stuff makes you quit a porn game?
Well, whether it's a sexual or not - that depends on the point of view. And to answer your question - too much talk, too little fuck. That's number 1 reason in principle, no matter the game. That's the main reason I stopped playing "Extra Credit" & "Tomboy Supremacy". Even when there was some fuck, it was between the MC and some demon, not daddy fucking his daughter.
First of all, as my profile suggests, I'm only into incest fuckfests! If the game ain't incest, I don't waste time with it. And if there's too much talk, too little fuck or no daughter fuck - moving on to better games.
Secondly, if I wanted all talk games, I'd just play the regular non-porn games that are out there on the gaming market! There's no point or need of beating around the bush: every single one of us is on this forum either for playing porn games, or for making them. So when we download a game, we expect a fuckfest - incest or not, depending on everyone's taste.
Coming to think of it, there are quite a few porn games on Steam that can easily be turned into incest with the ingame tools and these games have more fuck, less talk than "EC" or "TbS".
Poor graphics or not realistically enough looking girls (too big on everything - asses, boobs, pussies (yes, that exists too) or generally - bodies), or even looking like the things on "Sisterly Lust" - that's definitely a thing to make me quit a game and never look back. For that reason I never spent more than 5 minutes on "23 Sisters". Or the 12 seconds on "Sisterly Lust" - once I saw the creatures that were supposed to be women...