Metaphor, since you like making up arguments that don't exist to push a point here's one for you that does exist. When the KKK throws a parade do black police officers have to protect them or can a black police officer refuse? I'll give you a hint, regardless of an individual or groups’ beliefs or ideologies, they are entitled to live without the fear of physical violence (at least in America, I have no idea how they do it in Australia). The Baker is the black officer in this scenario and the customer is the KKK.
In my opinion, no one forced this Baker to go into business and the Baker should be well enough aware that not everyone shares the bakers' tastes in cake. If you don't want to have to do custom cakes you don't like then pull the fucking sign down off your shop and say you don't do custom cakes.
I don't agree with this.
Yes the KKK has the right to protest and parade in public.
But the police officer cannot be compelled to wear a white hood.
A cake maker can refuse to make some things. But they have to refuse to make those things for everyone. No racist messages for anyone. No profanity for anyone.
They can't make a cake celebrating some things and not make a cake celebrating something that is perfectly moral and does not harm anyone, based merely on delusion.
The government is blind to religion. It does not derive legal principles from religion.