Call an obnoxious speaker a jerk: what a useful formula, what an intelligent way to get the resentment off your chest without starting down the legal road to suppression of speech. It would have worked well, for example, in the notorious case of Prof. J. Donald Silva of the University of New Hampshire.
I find this section to be a disturbing summation of the author's attitude on the subject. And, the Groucho Marx quote has no bearing on any of this; it's self-deprecation.
Walled gardens are for suckers.