US-Porn, white women, black, anal

Hi,
why is every 2nd porn about an american woman getting fucked in the ass by one or several blacks?
Seriously. Right now there must not be a single woman in america that did not participate in a porn like this.
What is going on there in the USA?
Are the white men some sort of castrated homos or something like that?

Ender's Game (1985) is the best-known novel by Orson Scott Card.[1] In a future where mankind has barely survived two invasions by the "niggers", an negroid alien race, the world's most talented children, including the extraordinary Ender Wiggin, are taken into "Battle School" at a very young age to supply commanders for the expected Third Invasion.