Oh wow, another race thread. At the end of the day, the industry can't force people to have sex when they don't want to. If a performer doesn't want to film interracial scenes it's their prerogative; if that means a loss of income or the potential to lose future gigs as a result then that's on their head. Maybe the people involved have unhealthy attitudes, maybe they don't, but ultimately it seems to me an uncomfortable issue to be questioning people on their choice of sexual partner--yes they might be getting paid for the sex involved but you still can't force their hand regardless of their reasoning.
EDIT: Remember about the infographic in
this thread (thanks Siri) which suggests that only 53% of performers will engage in interracial scenes. Call me naive but I find it hard to believe that nearly half of the industry is racist, so there's got to be more to it than first blush suggests.