Re: This was an /r/science AMA
People don't care about what the title of the subreddit is. That Zuckerberg receives so much vitriol on a discussion of a completely unrelated topic tells you that most folks don't give a shit what he has to say on science issues, and these folks will gladly flaunt those fake internet discussion rules to take shots at a man that is dumbing down the Internet for his own personal gain.
Discussion rules don't apply to universally hated figures. People know that he's using the AMA and the touring to distract from the problems he's causing, and the comments are going to reflect that regardless of how much money is spent to squelch them.