With having 6 kids and seeing the changes that have taken place, I have to say that what I think is happening is society is attempting to push children to a level that they, in many instances, are incapable, maturity wise, ready to handle.
Then add a household where the kids are latch-key (which ours are not) and they have no parent to vent, talk or ask help from until everyone is finally home and exhausted.
You see these ads where they suggest the family eat dinner together at least once a week...WTF...that's a family?
Sorry, we eat together every night, we talk about our day, the kids vent, ask questions. Home is suppose to be the haven from the outside world and I think a lot of kids no longer have the safe haven and that adds to it too.