Here are some issues people should consider.
Professional Photographer: Asked to take pictures of nude people. Should that be the call of the photographer or the customer.
Has he advertised that this is a service he provides to customers? If not, then he is under no obligation to provide services to anyone that he does not advertise he provides. Now, if he takes nudes of
women, and a
man asks for a nude, and he refuses, the man would have a case.
Professional Baker: Asked to design a cake with a gay theme, a satanic theme, or a US Flag burning.
Now, you are getting into a different area fro the wedding cake. The
Baker v Hands On case, in Kentucky has set the precedent that if one is asking a business to create a
specific message that is contrary to the business owner's conscience, the business owner has the right to refuse. Once again, the only message sent by a wedding cake is "A wedding is happening here".
Private Teacher/Tutor: Asking teacher to teach Creationism when said teacher knows the truths of evolution/adaptation.
Unfortunately the critical word there is
"private". The government has very little control over the practices of private institutions that do not take public money. So, yeah. The school has the right to dictate their curriculum.
At what point is the business owner able to say, "This is not a good fit for the two of us. Allow me refer you to someone else."
When that decision is made as an
individual assessment, not based on a
class of people.