To be clear, I wasn't really expressing much of a personal opinion, just thinking about the difference between the two and thinking about the profound shift in acceptance of gays in society in even the last decade.
Personally... I'm not religious, I was raised an atheist, I don't like religion, and I don't really think it should be protected, but I sorta kinda understand why it is, religion seems "special."
Veteran status is also protected under employment discrimination law, and military service isn't an innate attribute, however, its in the best interest for a country to protect those who have served it, especially those who were drafted.
Family status is protected under housing discrimination law, and having a ton of kids isn't innate, but some can say that the urge to have children is actually innate. (Though as a person who never felt an urge to reproduce, I have a hard time actually understanding this)
So yeah... we aren't 100% consistent.