Possibly because once you label one group a victim everyone else naturally goes "what about me?" I think they're right to as well, because pretty much everyone is oppressed to some degree; if you're short you're oppressed, have you seen Tinder? "I'm 5ft8 so tall guys only", if you need glasses you're oppressed, obviously, those things are expensive! If you're homosexual you're oppressed, disabled, poor, have a mental illness, a dietary requirement, if you're ugly, it never ends, and how do you weight that? Who gets to decide?

I'm in part paraphrasing Jordan Peterson here, which might become a cliche soon, but I think he has a great point https://www.youtube.com/watch?v=-XvI6Y5Yq8o