Aircrash. Leave your bags, shout onlookers, afterwards.

Yes, we all agree that you get out without delaying and thus endangering yourself and others.
So why did people grab their bags? In the Asiana Airlines crash at San Francisco, bags came hurtling out of overhead lockers. Better to carry them out than leave them obstructing aisles and exits. Those first out are in the seats by the exit and can grab their stuff. It's an instinct. Obviously you don't delay yourself and others. But you must keep your passport and credit card in a pocket. Otherwise when you get off the plane you cannot prove who you are, pay for your medical expenses and hotel and fare home. I read about the people who survived the fire in the hotel in Florida years ago. Those by the pool without identity were stranded without clothes or money or identity. That's another reason to dress for the destination. If your luggage goes missing, you need to be dressed for the place where you have arrived. I got out of a broken down coach leaving behind my camera. While I crossed the road I was worrying about my camera and got hit by a car and nearly died. I'm all for taking luggage with - if you've time to grab it.