In point of fact, businesses operating in the jim crow era would likely also have chosen to not discriminate against a growing customer segment.

Laws are enacted to constrain the freely chosen behaviors of men. If Business owners were so racist that they didn't want black folk eating at their lunch counter or riding at the front of the bus then those restrictions would have been policies and not mandated by law.

The fact that those laws had to be enacted in the first place is arguably evidence that businesses generally do not want to discriminate, even at the high water mark of widespread racism.