Maybe they are just people who do not realize that they can save enough to do something big in life? Maybe they realized they could do this and have small happy moments and that's the best they could hope for? That's the thing that is lacking these days, people lost hope, any hope that they could live a better life.
They think that no matter what they do, they won't live a better life, and that means with debt the best they can do would be making a life that would have some stories to tell. I am one of those people, not that I spend it on irresponsible ways, but I lost hope, I can take out any debt I want, but I do not see any future where I can live a richer life, that just doesn't make sense to me at all.