They don't defend free speech; they abuse it. I cherish the right to free speech and do not think they should be censored, but to say they defend free speech is to imply that they are championing the freedom for the freedom's sake. They are opportunists that use free speech to spout their messages of hate, and they would cease to be proponents of free speech the moment they stopped profiting from it.
Even if the open windows of science at first make us shiver after the cozy indoor warmth of traditional humanizing myths, in the end the fresh air brings vigor, and the great spaces have a splendor of their own - Bertrand Russell