My objection to speech restrictionists is that they rarely give a robust mechanism for deciding which speech should be restricted, a mechanism that's hardened against people abusing it to further their narrow self-interest.
Speech restrictionists also tend to ignore the "circular dependency problem": without anyone to defend a position, how do we know if that position is defensible? For example, suppose you live in a theocracy. You're an atheist. You start making your case for atheism. Just as you're about to make your case, the theocrats interrupt: "This speech is killing people. It's preventing them from reaching the blissful afterlife by converting them to atheism. This person is attempting eternal murder." And then throw you in jail.
I'm in favor of a well-designed terms and conditions for a platform like Facebook. But I also think it's too easy for people to say: "I don't like what you said! You shouldn't be allowed to say it!" The de facto impact of that rhetoric essentially amounts to mob rule.