The reason they are "obsessed over", or taken into account as someone else may put it, although I'll give you that any kind of social/cultural identity tends to lead to some form of obsession in some people's minds, is because they are deemed significant for locally dependent social/historical/political reasons which I am sure I don't need to give you examples of but will anyway : colonialism, slavery, genocides... You name it
Whereas discrimination exist based of height, weight, and facial symmetry, because they are a little less based on cultural factors, they tend to cross group boundaries and not allow for culture wars because of its more evenly distributed nature.
The interesting thing is that the fact that you took the time to write a comment about them and that they are becoming a social issue is because the culture spheres tend to be bigger and more intertwined with globalization. People who share the same issues can find eachother and aggregate across cultural identities. The incel "movement" is a product of the world wide web, I don't think it would have been possible in another era.
On another hand, I don't think we need to establish hierarchies between discriminations. Although discriminations share a lot of their logic, they also often respond to their own logic. I am all in favor to put in place more mechanisms to avoid it, like any kind of anonymization, but I don't they are an argument against what's already put in place against more socially recognized ones.