Problem is that well-intentioned rules with discretionary boundaries end up with unethical enforcement. See: the bill a few months ago that federally defines “anti-semitism” as including “criticism of the state of Israel”. Actually that’s not even a discretionary boundary, that’s statutory. The reasoning behind the First Amendment in the first place was to avoid authoritarian censorship, including these kinds of games where “reasonable regulation” of speech is used to shoehorn in authoritarian censorship.