my 2 cents:
i watch many different genres of porn (straight, gay, lesbian, TS, ect ect) and while I have zero issues with black males in general, it's very hard not to find the seeming majority of them in porn who don't annoy the fuck out of me. i hate the thug acting guys the most. nothing worse then seeing a teaser of a good looking black guy with a hot girl and having him say almost nothing. the gay videos are by far the worst though. so many times they say NOTHING except "shit ni**a" over and over again. super lame.

that being said i LOVE black women and the ghetto girls in porn annoy me as well.
i guess for me it's less about the skin color and far more about the attitude in the scene and it seems that skin color breeds more of that attitude