Earlier quoted context omitted.
I'm not saying you're anti-leftist, simply quoting someone's take on the psychology behind P.C. bullying. Not everything has to involve left/right-wing tribalism.
You say as you post a paragraph from a (whoops: not dead) terrorist's tirade against liberals. I don't think you could have possibly picked a worse example to hold up as not involving tribalism...
Judge the quote on its content, not the messenger. The only instance in which shooting the messenger is valid is when we rely on the messenger's credibility in evaluating the opinion, which is not the case here, at least for me.