Opinions and ideology might be mutable but they are not a choice. You get convinced into them, this is not something that you can just choose.

Anyway, I would argue that simply protecting immutable characteristics without also protecting certain actions does not make sense. For example it makes no sense to protect sexual orientation but not the action of holding your partner's hand in public or publically saying that you are of a certain orientation - after all your employer/person that you are doing business with would likely not know your sexual orientation without doing either of the above actions.