Why would those even be exceptions or treated differently.

I find it a rather arbitrary standard I so often encounter.

How would banning for religion be different than banning for any other opinion? So long as an opinion asserts the existence of a higher being it is inviolate? All I need to claim to be unbannable for saying that vaccines cause cancer is simply add “This was told to me by the almighty creator Zefron of Zefronism” and that small differences turns an ordinary falsehood into a religion?

Can I deny the holocaust in Germany by simply making it a tenant of a religion?

It seems awfully arbitrary to me.