While I don't agree with Dakota's sentiment, here's a different spin. If Dakota had written, "no women" would we be chastising him just the same? Technically, a woman could use RM to hire escorts. So are escorts on RM obliged to serve women? If they refuse, are they sexists? Are they putting women down for refusing to serve them?
I totally understand why his note has struck such a raw nerve and I can totally understand why people are justifiably offended. However, I'm not sure the rules of discrimination that we can apply to lawyers, doctors, etc necessarily work for escorts. For an escort to be good at his/her job, they have to establish a chemistry with their client. If the chemistry isn't there, there's a good chance the client won't be happy. Attraction is part of that chemistry, though certainly not the only thing.