In fact, the very ideologies we consider "detrimental to society", to put it lightly, e.g. Nazism, Communism, were "detrimental" because one tenet of those ideo

In fact, the very ideologies we consider "detrimental to society", to put it lightly, e.g. Nazism, Communism, were "detrimental" because one tenet of those ideologies involved banning ideologies which it considers could lead to detrimental outcomes for society. It doesn't really matter what the ideology believes, the only thing that matters is what the ideology advises its adherents to do, or not do, to people who do not adhere to the same ideology. A government of egalitarians intent on censoring, torturing and quartering every racist and sexist it can find, en mass, is no different to the evil that was Nazi Germany.