Well, in my opinion a lot of it is because there are so many conveniences that help you stay poor!
For sure - we are lazy by nature - so if we can satisfy our immediate desires easily, we do - even if it costs us down the road.
Globally I think that many people are working at the wrong thing - chasing a paycheck, not real independence.
There's this thing people say "If you know, you know". In this case, it's a bit of a "if you don't know, you don't know". On the example of my parents, I can tell that they're not necessarily dumb people - but growing up in communism/socialism-ruled Poland and then in the inbetween times, they did not have the resources to learn how to get out.
They work hard, they aren't at the lowest lows of the food chain, but still it is not like they know how to accelerate their savings - and they're reluctant to take the risk to do so while they're approaching 50+ years of life.