A business that serves the public must treat all customers equally. Anything else is, indeed, a crime. A business is not a person and doesn't have the same rights - nor is there any sane reason it should.

And as I pointed out before, here in South Africa, that's actually a criminal offense as per the HIGHEST law of the land. And that's damn good thing. It also has had exactly ZERO negative outcomes, and lots of positve outcomes - and that's despite us rarely ever invoking the criminal law on discrimination cases, we usually just have them settled by the equality court.

http://constitutionallyspeaking.co.za/news-flash-folks-private-discrimination-is-illegal/
It's a crime.