I'm not telling you how to behave, I'm just saying that if you had thicker skin you would probably make more money, so another way of looking at that is that you're paying a premium for the luxury of being able to be, let's say "honest" then, instead of rude, to your customers.
I understand that and agree, but yes, I ascribe a high (societal) value to telling people when they're being rude, because I think to do otherwise is to enable them.
Besides, people like the customer in question come once in a decade (to me, anyway), so it hasn't been a problem.
