Although technically I'm not sure this is a bad thing out side of economic cause. The Western 'you move out when you come of age' model is unrealistic, and unsustainable, at least for the near future.
There's significant argument that this is a detrimental effect on our culture in the west that's driving isolation between person.
That's not to say that the causes that you lay out here are not worrysome problems of the highest order.