I'm following what you're saying, but the SCOTUS didn't really weigh in on that. They merely defined a case where the Colorado anti-discrimination law conflicts with the first amendment freedoms of the store owner because, owing to gay marriage not being legal at the time, making the cake would represent speech indicating the position of the baker in conflict with his religious expression. Without the CO law, it's my impression that they could discriminate against serving them any way they wished for any reason. Which poses an interesting question. In the absence of legal protection, are there people who cannot find services from anyone? Is that ok? Imagine this were 20 years earlier in the South. Would it be acceptable for them to be able to find no one to make them a cake at all?