I think a classic rebuttal is "would you be OK with a bakery owner turning down people of color based on religion"? How is turning down homosexuals any different?

Genuinely curious what your take is. I think the topic of the bakery owners is so widely known because of this. As the other reply said, and your discussion has continued: I believe that it ultimately comes down to what has "arbitrarily" been decided as a protected group. ("Arbitrarily" in quotes because it is ultimately the American political system in this case, and that's not really arbitrary.)