I'm not defending Elon's behavior here, but speaking more generally: if you're in a place where you need to maintain maximum productivity for a while, because a deadline has slipped for example, meetings can turn into a massive time sink if you don't act like a total nazi during them.
In so many meetings, people just want to hear themselves talk, whether to offer some opinion, reiterate some point, or ask some useless question. If your goal is, "end this meeting as quickly as possible so I can start fixing the things that need fixing", often the other people in the meeting become your careless adversaries.
edit: I regret trying to raise this point in a thread about Elon Musk. :-(