I mean people can be bored or hate the manga, but I don't think it's fair to analyse it without some context. What i'm about to say doesn't mean i belive that this series is factually better that anyone thinks, art is subjective and doesn't have to represent the values of society or individual people.
So this is "the girl isn't a virgin" manga, but we are all aware of other manga tropes, tags and stereotypes. There is an obsession with virginity and the fact that it's the girl that falls in love and chases the MC, that also seems pretty unhealthy. That and a lot of other things that can be classified as "toxic masculinity" or bad moral values or whatever, thats not my point and this is not twitter.
I'm on record for saying in this comment section that this manga is a character study of meguro, the "kuudere slut". That may seem like giving too much credit to the manga, but I think it's better to see this as a story. Many stories start with a character with a flaw that comes into conflict with the world around them, in this case the view that Meguro has on what is a relationship is challenged by the relationship with Koga.
The problem is that characters in this manga are made around their flaws and not the other way around (making a character and giving them a flaw they have to overcome). There is no character outside the "simp" for the MC because that was his defining characteristic. The same way with the "kuudere slut" for the FMC. This exacerbate their flaws which can make it hard to watch for some people. To me this is always the wrong move, not just for this manga but for storytelling in general. But if you think about it its not so different from other gag school slife of life romance, the difference is that the tropes those characters fall into are well stablished. Meguro is a bit of a "taboo" in manga. This is not to say she is the first of her kind or that she is even well done, just saying she is not a mainstream type to be presented in this way.
This doesn't make the series good or morally better or worse, i dont care about that. Manga as an industry and art media can be improved by defying the stablished stereotypes, not for social justice or whatever if you dont like the word, but because it helps diversify stories and not have just thousand of mangas that are exactly the same (refer to the hellscape that is isekai and every fking school romance)