Is it possible this is more apparent because the industry is so young compared to the other professions?
Historically most programmers have gone into other industries or management, however with more programmers today in their 30's than ever before isn't it possible that the average age of our profession increases?
Perhaps it's just because I know lots of entrepreneurs that are much older, in their 40's - 60's that consume massive amounts of new information and enjoy doing so that I don't fully agree with your statement.
And about Facebook, I am sure there were lots of other social networks being formed around the world by young people that feel over too.
I am not sure that is such a old vs new thing.