You obviously haven't been punting long if you think that. BW will tell you himself how many stories he has heard from his ML friends about just how common it is for punters to run out without paying.
I have even heard of punters walking out of a shop totally naked because the ML was holding all his belongings when he refused to tip. So basically he went in there with the intention to leave everything behind if he got caught.
You make it sound like these girls are all rolling in cash from performing this wonderful and illustrious job. I am sure you are such a handsome and wonderful catch that the girls just feel privileged to be giving you extras. But there are some absolute disgusting pigs out there also. If you think they girls are paid too much, ask yourself how much you would be willing to accept if you were asked to do the same service.