If either buyer or seller does not wish to any contract including the cake-baking for whatever reason then they are entitled to refuse. If a buyer has right so does a seller
If I asked a printer to print me a large placard saying, THE BIBLE SAYS HOMOSEXUAL ACTS ARE SINFUL, which is undeniably true, and he refused, I would concede that he has every right to refuse and go elsewhere. So your inflammatory accusations are patently false as usual.