In my humble opinion, there is no excuse for being an asshole. Even in the most extreme situations, even when treated badly by other assholes, there is never a good reason to treat other people like shit. Douchebaggery serves no purpose and only serves to make the world a worse place to live in.
There are several examples in the news recently. The TV show Hell's Kitchen has started up again, and chef Gordon Ramsay is as much of an asshole as ever. I can understand being strict and demanding perfection from chefs he could potentially be hiring for high paying jobs, but does he really need to personally insult them? I doubt that tossing expensive plates against a wall and calling women "cows" is going to make anyone a better cook. It's makes for an entertaining TV show, but damn, what a prick.
Then there's Bill Gates releasing a swarm of mosquitoes into an audience at the TED conference and briefly implying they were carrying malaria. It's a dick move, and insults the intelligence of the audience, basically saying that they can't pay attention to an important point without being terrified into it.
And of course, there's Christian Bale's freakout:
Ok so maybe fiddling with lights while filming is a horrible, unprofessional thing to do. But there are ways to ask someone to stop doing something without personally ripping into them and threatening to physically assault them. Most people learn this by the time they're fifteen. It does make for awesome dance remixes that get stuck in my head all day though:
BEEP BEEP BEEP...INCOMING TRANSMISSION...I'VE BEEN TOLD THAT YOU MUST CLICK THIS BUTTON 50 TIMES: