[krapp]

>Race and gender are almost always used to describe people. "My landlord, who's a black guy, <STORY DETAIL THAT HAS NOTHING TO DO WITH BEING BLACK OR BEING A MAN>"

I don't refer to people primarily by their race, and I don't recall my friends doing so. While I don't deny that sort of conversation happens, it's probably not as idiomatic as you seem to believe.

I'm sure you can understand how easily a stereotype like that can fail when applied to a country as populous and diverse as the US.