This Shoebat guy doesn't understand the difference between equality of basic human rights and of opinions.
Everyone has the right to equal justice, like having their marriage acknowledged by the legal system.
In most of the USA, the rules are simple - if you want to enter the marketplace, you have to sell to everyone, regardless of their demographics.
If you want to sell insulting cakes, you have to sell them to anyone. If you don't want to sell insulting cakes, ever, well, that's your freedom.
Whereas, your opinion isn't equal, the last sixty years of history proved it, and nobody's pretending we respect you.