This is not a good argument, as it implies that if science finds a way to change sexual preference then the protection should be revoked.

Also political views can not be changed easily either, it requires exposure to facts during a long time in a way that would circumvent brain's desire to be right.

But more importantly the right of companies to refuse service as a substitution to real justice is not going to fix society, it will only make things worse when bad guys get the power. Justice requires rules, not arbitrary actions by private companies.