I just don't think they would get any customers.
Well, obviously. Women don't tend to be punters. The only customers would probably be some sex-pozzies who think it makes them look sexy, and they would only order coffee, either.
But I think there's some potential that the MRAs would throw a tantrum.
It's like a fashion that it's okay for everything you do to be "out there" and part of this is "let's get a blow job at the shop".
I would prefer if men weren't punters in secret, either. It's horrible that this is considered acceptable, but it is nowhere on the same level with filing your nails in public - filing nails is a perfectly acceptable activity, just one that many people would prefer not to watch.