"I like everything about this game except the art" absolutely does explain why someone might complain about the art. I think the problem is less that I didn't provide an explanation, and more that you never really wanted one. You just want to complain about people complaining.
I did offer valid criticism. The definition of valid is not "something petekron agrees with." I don't go to every real-porn game and say I don't like the art; the only reason I brought it up with this game is because it seemed like the dev was trying to go for Patreon money, and real-porn is just not something you see in the top Patreon earners. "This will make it harder for you to earn a lot of money with this game" is about as valid a criticism as you could ever ask for. Again, it doesn't seem like your problem is with the validity of criticism, you just want people you disagree with to shut up because you disagree with them, and you can't handle a world in which more than one opinion is valid.
As for just ignoring the thread, I've also played
Company Man (which is kinda like a more fleshed-out version of this game). Go ahead and try to find a comment from me in that thread complaining about the real-porn. I didn't bring it up there, because I'm fine with the concept of it being really hard to find a game I'll 100% like. I did bring it up here,
because the dev was actively looking for feedback, and this was a valid criticism, whether you personally agree with it or not.