Or, I guess you could say, it goes back to the lack of a depression since the 30's. You're right that most pre-boomer and boomer kids had a pretty easy life.
The whiners are rapidly becoming a majority, which gives me considerable pessimism about the future of the nation. California's sort of the prototype for what happens when you can get elected by promising the voters the most freebies.
This was a problem for a lot of Roman history, and it caused the fall of the Republic, for sure, and allowed the political instability that allowed the rise of the Emperor. And the way it played out in Athens gave democracy a bad name for many centuries.