male social circles-- especially ones based around physical activity-- are cliquey. always have been.
urban cycling is no different. the newest new jack will get snubbed or mocked until everyone finds out he's got a 35mph sprint in traffic. if you don't have prowess, then you have to pay your "dues" within the social structure.
that's just how it goes.
in highschool, you saw it with jocks. every group has it, it's nothing new.
females aren't nearly as common in circles like these, so they're usually quite surprised when they encounter it, as OP is.
it's been around for tens of thousands of years.