I guess I'd have to disagree here. I think that there definitely should be some restrictions on who you can ban from patronizing your business (such as forbidding businesses from banning racial minorities or homosexuals); I'm just not sure whether I think something like limiting based on age (outside of enforcing the legal drinking age).

I'll try another thought experiment which is a bit more similar to the real-life situation: do you think that private entrepreneurs should be able to ban people over a certain age, e.g. everyone above 50?