Yes it should be. That is the very essence of the line of seperation between public and private. It is also the line of seperation between freedom and tyrany.
If a certain clientel, for whatever reason, is not being serviced then a demand is created and more business can be expanded.
Based on your arguement, a business can deny service to anyone as a matter of personal choice. So you have no problem with blacks having to sit at the back of the bus or being denied service because a private restaurant only wants to serve white customers. Just let the free market create a business that caters to blacks, or to everybody. Thank you for proving you support racism, discrimination based on disablity or even very basic health and safety standards. You disgust me and I will justly ignore you.