My humble opinion, after having been on some threads for a little while, is that in general the average user doesn't care about anything but his/her own self-enjoyment. And that egoistic attitude transpires not only through unconstructive criticism, but through the even more annoying and more spread custom of posting questions that have clear and repeated answers throughout the thread and that sometimes are even answered in the OP. Why do people do that? Because they want immediate response to their problem without having to search, so that they can go back to their business as soon as possible. And the same self-centered attitude is seen in criticism. They don't critique because they want to improve the game, they critique most of the time because they can't accept that a game could be catered to people other than them.
Thus the "why RPGM", "why cuckhold/NTR", "why the scene goes this way and not the other" kind of comments the net is full of. It's pretty clear that the answer to this questions is that some people like different things, but those comments and their variants keep piling up because people need to project themselves and their tastes onto everything.
And the reason for this attitude is usually that those users get the product for free (we're on this forum for this reason, after all) and so don't reflect on the fact that it's them who should filter content based on their tastes and not devs who should cater necessarily to them. If they had to pay for the games, they wouldn't ever bother to buy, play and comment on an NTR game if they're not into it. But for some reason if it's free they go for it and then complain that the game is unplayable because of the genre.
A lot of people feel entitled, they think that they hold some kind of right on the dev's time and toil, they think they can tell devs what to do, how to do it and for whom, as if being a porn game developer was some kind of holy office meant to be carried out for free in service of the community.
And since they feel entitled and care only about themselves they often comment without providing valuable feedback, because those comments aren't actually for the dev to improve the game, but for them to vent their anger at a game that fails to fullfill their egotistical expectations. They are offended that someone is trying to waste their time, even though they don't pay anything for the game and could just filter it out.
