Everything is connected and it may sound absurd to link contraception with the economic collapse, but think about it: 

History will look back and decide that artificial contraception was the most radical and earth shattering invention ever devised by mankind. When the link between the sexual act and procreation was broken it not only changed our sexual behavior, it changed everything.
Most importantly, it changed the way we think about ourselves and our actions. The links between our actions and their natural consequences were broken. We began to expect that we could have whatever pleasure we wanted when we wanted and how we wanted and that we could avoid all the consequences of those actions. In sexual behavior it seemed to be so.
We became gods. We could do anything and have anything and we could avoid the cost. Extrapolate this mentality to the economic sphere and you’ll see what I mean. We told ourselves that we could have anything we wanted instantly simply by taking out another loan. If we were the lenders, we insured ourselves against loss in case those loans were not re paid. 
The responsibility could always be shifted. The ‘problem’ could always be solved. Paying the price could always be delayed.  We could just re-finance. Just as we got instant sexual gratification for free, so we thought we should have everything else instantly for free.
How different our mentalities would be if we still understood that every time a man and woman come together a baby might be made. If we lived that way we would have to grow up and be more sober about all things. We would have to take responsibility, and if we did not the consequences would meet us very soon. 
Instead we have become a society of spoiled brats. Stamping our feet and demanding instant gratification and entertainment and pleasure, and believing that somebody else somewhere will pick up the tab.
Where did it come from? I realize the causes are complex, but a contributing factor is artificial contraception which changed the way we think and respond at a very profound level.