I think it is classic "racist", it is almost word for word racist like in the restaurant and hotel signs from the 50s and 60s. "No blacks allowed".
Sure, we don't look to providers for their take on civil rights and not all providers are like this. The OP and others can certainly go elsewhere. But let's at least call these kind of posting bad for business and bad for the hobby. What is the opposite? "I welcome everyone and love everyone". I would much rather see those posts than those singling out people to exclude.
And what is there reasoning behind the posts? I bet some of providers end up seeing a bunch of thugs (black thugs) and think that all AA men are like that. That isn't the case. What are you going to refuse Obama? You might word your posts, "No thugs or smelly, convicts". I don't know.