Do you think that changes the liability?
Well I was messing with you, giving you a hard time for advising a business owner to be a wimp and just shut up, go along, to get along. That is the net result of your advice by the way.
BUT - I don’t think this stupid sign, that does not even appear to be official government signage, changes the Constitution. There are pockets in this country where businesses have lost the ablity to refuse service, but such is not the law of the land. Businesses, by and large, do reserve the right to refuse service. If we capitulate on that, we will certainly lose it totally one day however.
Anyone can be sued for anything at any time. If you live in fear of that, you are a sheep.