I guess in some businesses where you need to attend the wedding I could see why there is opposition but ultimately the desire to not want to bake the cake doesn't really hold up well. Discrimination laws are a thing for good reason if we do actually consider sexuality to be innate like race than the law should apply to the same degree. Restaurants may be able to say we have the right to refuse anyone but if you turn away all the black people you are going to get rightfully sued for discrimination.

Plus what if a Muslim, Atheist, Buddhist or Jew asked for their cake to be baked? Would they refuse them too? Are you a Protestant going to do business with the idol worshiping Catholics? It's not like the Bible forbids doing business with unbelievers or sinners so to me I don't really get their point. At the end of the day they just want a license to discriminate and if we do allow people to do that it just creates more hostility and head aches for everyone.

The only argument where I can see the point is say the right to discriminate in organizations that require religious belief such as churches, religious colleges, catholic schools and the like where adhering to the moral code may require some aspects that not all agree to. I think that is fair as long as again it's not infringing on others rights (you can't advocate to kill people who don't conform). A business though is not a religious organization it's a secular one.