The real answer of course is...
Boomers. Largest demographic in North America. They are old now and dying of... well... being old.
Just like there was a slew of them in the sixties and seventies because they were still in that "young and stupid" period where you are more likely to die of misadventure.
So the ones who made it to their early to mid-thirties without kicking it are kicking it now.
In another decade or so the rash of old punkers, new wavers and 80's pop stars will begin.
After that the grungers.
And so on...