You ever notice how, if you're on the right, there’s only one name for you, you're "Conservative / Republican / Right-wing" used interchangeably and that's all there is to it.
But, if you're on the left, there are countless factions and sub-factions you can belong to. You can be liberal, leftist, anarchist, progressive, then all the little subsets of each.
I guess the good thing about lacking nuance is it's a lot easier to forge solidarity.