Other than a standard holier than thou attitude? It’s a typical hostile response towards anyone engaging in sex, as if anyone who dares enjoy it for reasons that don’t fit with the individuals own sense of views, without considering that each and every person views it differently.
Well, I keep wondering why your reaction is so harsh. I merely called this sort of arrangement shallow.
You're friends with somebody AND you have sex. So the only thing missing is love, hence the shallow (=loveless=involvementless=expectationless=commitmentless) form of a relationship. And AFAIK even the people who practice this sort of thing admit it's shallow. Not only that, but that's what they like about it! This is because it (seemingly) exempts them from any sort of responsibility and commitment. Most of the time this ends up with one of them developing some feelings for the other anyway, and then they usually break up any sort of friendship, too, out of embarrassment, which only shows how unnatural the whole idea of friends with benefits is.
Nowadays, people increasingly focus on freedom, including the freedom of relationships, but I think that one of the points of relationships is that they are inherently restraining. And that's the good thing about them! When you're in a loving relationship with somebody, you say something like "I know that I could be free instead, but I'm willingly giving up this freedom for you because I think you're worth it". And I think there's more value to it than to say "You know, we can have sex and be friends, but I'm not willing to give up anything for you because I value my freedom and I don't want to commit because, you know, that would require emotional involvement".
I think this is part of a bigger issue of separating sex from love, too, which might be why Gen Z wants less sex in movies. Back in the day, sex in movies meant a sort of forbidden fruit, engaging in a fantasy of crossing the social norms. It was the very basic role of art to use it as a means of experiencing something you'd be too afraid/ashamed/unwilling to experience in real life. But nowadays Gen Z holds no brakes anymore, and so they no longer need to dream. They only need to satisfy their urges, one way or another. And that this was also the case way before Gen Z might very well be true. But it's also true that there's a weird divide in Gen Z, with a part of them being more liberated than anybody before them, and another part being absolutely sexless, asexual, barren. It was way more Gaussian back in the day, I believe, but now the weird extremes are much more pronounced.
It the response that incels are made of.
It's funny you mention incels (indirectly calling me one, I believe), as incels are an interesting modern phenomenon. First, culture makes young men believe that the lack of sexual experience undermines their value. Second, that same culture vilifies them for suffering because of that.