I agree. Nothing and no one is exempt from judgement or criticism. This is exactly what some people seem to refuse to understand.
> Opinions, and speech, have power Nonsense. People have power.
> Therefore, some speech is harmful
We are past the inquisition. Word's don't hurt, they don't kill, they don't destroy lives. People do that. There is the argument that they can encourage you to do all these things, but does it really happen outside an "echo chamber"? Throughout history this happened only when conflicting opinions weren't allowed.
In the free market of ideas the bad ideas will lose and the good ones will win. It is inevitable that the best "product" wins. These people know it, that is why they don't allow others to voice conflicting opinions. They will lose. The only sane and healthy way to fight what you called "harmful speech" (i.e. the kind that encourages violence and/or discrimination) is through debate. If we silence people and destroy their lives are we really better?