I'm SLF so please forgive me, but many on here are missing a few critical points. Before I discuss that, let me first say that I would not grad my bag or anything before an emergency and that I keep my passports and anything not replaceable on my person at all times on flight.
The point that needs to be made is that current regulations, immigration and airline policy reward or at least encourage passengers to take their bags with them in an emergency. Examples I have read on this site over the years include:
1 - A crash landing with no fire (Asiana in SF????) where it took three days to return bags to passengers.
2 - A slide evac where passangers had to wait half a day in the terminal without any food / drinks provided to passengers who did not have any money / cards
Then, what happens when you are some nationality like Chinese or Indian and you land in the US and the plane does burn. Good luck proving anything to immigration!
The fact is if people are punished like this for doing the right thing, then nothing anyone can do will stop them from doing the wrong thing. That is human nature. The solution is to change the systems not just blame the people.