The industry does place a certain fetish on white actresses fucking black men, and some of it can get pretty fucking ridiculous. In an industry where the certain "new acts" an actress can do and get increased pay or exposure for can quickly deplete with each new scene (especially some of the tard talent that starts with a DP), its no surprise that "Her First Scene with a Black Man!" has become such a tag line or selling point.
It doesn't surprise me if there's some racist women out there who refuse to work with black male talent out of hate, but really how many porn stars out of the thousands regularly demand it? And how many have stuck with "no interracial" to the end of their careers?

If anyone's the racist, its the consumers who buy into some of this ridiculous shit...and hell, even the industry itself can even feel ashamed of it. Shit, I remember three years ago when some companies still had the balls to put "NIGGER" in their video titles. Now "negro-this"..."negro-that" is about as derogatory as it comes.