Damn. The white guilt is running strong. Also this plays into what I've heard from some of my European friends: over here in the US we tend to racialize things even when it's not called for.
This isn't your average business/profession. When you refuse to sell someone a TV based on personal attributes people rightly say "Hey, what the fuck!" When the business involves a very personal act (and no matter you think about sex it doesn't get much more personal than inside your body)? Different ball game. And the girls can't exactly afford to err on the side of niceness when the risks are high and kowtowing to PC culture doesn't get them a lot of points other than maybe (maybe) a wider pool of clients.
In terms of preference... yeah with some women it's a preference thing but I assume most of them would prefer not to see fat or 'nerdy' guys either. In the few discussions I've had with girls on this topic it seems to be an issue of risk. It's also not racism, it's a culture problem. Just like how some providers refuse to see AA men due to the prevalence of thug culture (not to mention black pimps hoping to recruit) but would actually be happy to see an older, professional fellow who just happens to be black.
Like it or not negative traits for this business (haggling, pushiness, disrespect, and even out and out misogyny) are rampant in the 1st and 2nd generation Indians and Middle Eastern men. This doesn't have anything with their genetics it's culture. This also doesn't mean everyone in that group is going to act that way. I've never heard a bad word said about notimportant, for instance. OTOH I've hung out in bars and clubs where the girls had a standing policy to stay the fuck away from groups of Indian men (for good reason it turned out) and I personally know of three providers who were/claimed to have been raped by Indian men. One of which was a gang rape.
It sucks, yeah. But I can see why they do it. What I think is just as disturbing is that a provider deciding who she'll do business with, when the business involves her vagina, she can be accused of racism for exercising her preference.