Aren’t they? AFAIK it’s standard (if not required?) for airlines to have insurance which includes passenger legal liability.
Were there any recent crashes where passengers weren’t compensated? e.g. after US Airways 1549 everyone received at minimum $5k (or higher depending on damages) for lost luggage.
On international flights, an airline is liable for up to $1700 per the Montreal Convention. This might cover say half of one's laptop, which no matter how stupid it sounds, makes taking your luggage with you the only financially sensible choice in a crash (unless you have insurance). Now obviously such an event has other priorities than just financial ones, but it's no surprise if people choose to take their luggage with them.
On US domestic flights the amount is somewhat higher, $4700. However even this might not be enough for some. On EU domestic flights it's 1800€.
Airlines however are free to pay any amount they want, but they are not legally required to pay more than the limits set by law. So it is possible you will be reimbursed in full, but you wouldn't know that beforehand.
If there's no smoke, no visible flames, and you can do so safely without obstructing other passengers' egress? I can see the argument, sure.
Obviously if the cabin is filling with smoke or there are visible flames or other obvious dangers, the financially sensible choice is to evacuate ASAP as funerals often cost more than laptops.
I guess my argument mainly is that people who take their luggage are not stupid, instead their behavior may be highly rational, however we have the means to change it with by making such choice irrational and I wish we will.