I walked into a liquor store without a mask. The guy comes out from the back room and says "you got a mask?" in a demanding way. I say "you want my business, or not?", and he says "yeah..." in a defeated sounding tone. I get some whiskey and say thanks, and that was it.
Small businesses should be ignoring this nonsense, but maybe he watches a little too much TV.
I'll usually wear a mask into a store, then take it off after I'm past all of the customer service people and greeters. Haven't had a single person say anything to me about it yet.