Earlier quoted context omitted.
Why should specifics of what is said matter if the point is free speech?
Free speech is necessary, but not sufficient. It isn't simply that the speech has to be free; it also must be worth exploring. To use my analogy, the Earth-centered model is free speech, but it isn't worth much, because it is wrong.
And yet in schools around the world people are taught that electricity flows from positive to negative, and everyone is happy. xD
(slightly disingenuous, but I'd say wrong and not useful are merely correlated rather than 1-1 linked)