A good critic can distinguish good composition, arrangement, and quality of production, regardless of genre, precisely because it is separated from the appreciation of the genre itself.
I think that we're talking about critique coming from the users of this forum, among which there are people like me, who just don't look at a picture twice if they don't like it and from whom nobody has anything to learn, and on the other extreme people who not only know a lot but who have the patience and skill to explain and to teach.
This is what one can expect in a forum, IMHO. I have seen both types here and a lot in-between.
BTW I was not talking of "genre" but trying to give an example of how I react to beautiful and to horrible things, call them what you may.
In "music" you may personally also define what's music and what is noise.
About "likes" and the like (pun not intended), If I show you a picture and you like it, I'm happy.
Because we share something. We have something in common, however little
If you don't, then you like something else. That's all ther is to "likes"