If you lose your ID or any other official documents in India, everyone knows how much of a hassle it is going to be to get these documents reissued. Of course the possibility of bribes to move the papers. Insurance claims for lost baggage? I wouldn't rely on it. It might take them a while to save up to buy whatever they might have in their bags too. Laptops, tablets etc. They probably don't earn that much to begin with. This is probably what ran through their minds.
Yes, lives are more important in the end and every second counts in such a scenario. But as an individual they might think - hey, it takes a few seconds to grab my bag and jump out. That would save me SO much trouble. Unfortunately that's what everyone thinks and in the end everyone goes for their bags and waste precious time.