protecting minority groups from psychic harms
This feels like bit of a misdirection; psychic harm, i.e. terrorizing the vulnerable is only the first-order effect of allowing the expressions of hate to proliferate; the secondary, and more important effect, is that the attitudes they express, if unchallenged, become viewed as commonplace, which is a signal not just to those being targeted, but importantly to the rest of the population holding these views, shifting the window of hateful expressions that are viewed as acceptable.
It's not difficult to see how this is far from limited to psychic harm.
(For the record, this should not read as a defense of censorship, but rather as a clarification of what I believe is at stake. Also, this is obviously not limited to the classic example of minorities and hate speech; analogous arguments also came from the right during the whole milkshake debacle.)