A couple anthropologists have told me that this concept is as old as all recorded history: the youth used to respect their elders better, that people were kinder and more pious, that these are the last days.
Oh yeah, there are Sumerian tablets about exactly this, someone around 4000-5000 years ago wrote:
Our Earth is degenerate in these later days; there are signs that the world is speedily coming to an end; bribery and corruption are common; children no longer obey their parents; every man wants to write a book and the end of the world is evidently approaching.
Socrates bitches about kids these days quite a bit.
If you go to today's grumpy old people, and openly emulate something their parents would have done, it throws them right the fuck off, by the way. In my experience, they still think mom and dad were uncool, and implicitly think they're from the only generation that did anything right; the good-old-days stuff is just a facade.