It must surely be some Internet Law that people who spend most of their time in bubbles where they converse with the worst of their opponents make the worst arguments to people outside the bubble.
So, if you take an otherwise decent smart person and place her in a spot where all her enemies are vitriolic morons, she will start to apply vitriolic rhetoric. Bring this person out of that universe and into the normal world and she will continue to act as if she is speaking to that subset. However, the normal world now sees only her polemic, not what she is reacting to.
You can use this technique very effectively to turn normal people into weird people. Surround them temporarily with enemies who are violent-sounding morons and then return them to the general world. It's the equivalent of everyone in a parking lot parking over the lines and then forcing the last guy into a space where he has to park over the lines. Then you leave, and everyone else coming in thinks this one guy is the asshole.
Of course, reading the article he is actually absolutely correct about these Hall Monitor scarlet letter "label the witch" people.