You'd be surprised by what turns people on. Some dirty old farang out there has a fetish for getting down and dirty with an ugly East Asian MB.
That said perhaps the role of the mamasans needs to be redefined altogether. Can't have one just because everyone has one. After all it is a competitive environment. When you interact with a mamasan you should feel like you have an ally looking out for your best interests. Of course they want your money but shouldn't be so blatant about it.