This isn’t slavery. Slaves can’t quit. This woman could quit her job at any time. Slaves don’t get paid. This woman not only got paid, but had the freedom to set the prices herself.
If you want to oppose all non-discrimination laws, go right ahead. But I certainly hope you aren’t one of those people who is complaining about how unfairly Ivanka Trump is being treated or something silly like that.
Basically, your argument is that Whites Only lunch counters should have remained perfectly legal. You can argue that, but it’s not going to make you very popular.
In my experience, people who argue in favor of the ability to discriminate are people who never have and never expect to experience discrimination in their lives.
The difference between the Rockettes and the florist is that the florist discriminated against an entire group of people based on assumed characteristics, and the group has no control over the characteristic that makes them part of that group, being gay. Donald Trump has complete control over what he says and does, and the Rockettes objected to him for those reasons, for what he has done, not for something they assume about him.