"wait Rattigan350 so are you fine with a restuarant owner not allowing black people to eat at his restuarant in this day and age?
But why isn't it the same?"
No shoes, no shirt, no service. Business can set codes of conduct for customers. Forcing people to do work they don't want is slavery.
Photographers are mostly sole proprietors. In which they can refuse to do any work they want. I had a small business and I could make up any reason to not do work for anyone. We don't do that job, we are closed, our equipment can't do that, etc. But then they don't get paid. However as employees, the person can refuse and the company can assign another employee to do the job.
While restaurants can put signs up that say "Whites Only". It is private property and they can do what they want. But it is bad for their business. The Jim Crow laws mandated such things, and did not make it a choice. It is like Branch Ricky hiring Jackie Robinson. He did that because why not get all of that money from the black fans.
Today, if a racist waiter sees blacks at a table, he can refuse to serve them and tell another waiter to server them. If the business did something like that, though, the negative press would shut them down.
America was founded on Freedom of religion. That then became extended to other groups because of bad treatment to them. Women gained the right to vote and equal pay. Blacks gained rights. Now abuses are illegal. If people abused gays, then that is illegal under the assault and battery laws.