And yes, there is probably SOME GUY out there that does. It's a trend, not an absolute rule.
However, even if there is a trend to be observed, the information is only useful to someone trying to select from a group of candidates, and then only if the selector is unable to distinguish between candidates on the basis of the desired characteristics. The trend is of no use to the candidates.
Thinking that you have an advantage simply because you are young is foolhardy. Lamenting that you are at a disadvantage because you are over 30 most likely reveals your lack of fortitude. You either are (and intelligent curious dedicated &rest important-attributes) or you are not.
So another risk is too much awareness - rather than being technically clueless, the older crowd goes too far in the other direction.
A handful of genes separates a human fom a sea cumcumber (ok, maybe a little more than a handful)... uhh, how is this different from using DNA to make more DNA? ;)
Point well made.
But in theory it works both ways - older generations might see business opportunities the younger ones are missing. I know I wish I had thought more about certain things when I was younger...
And since society seems to be aging, the advantage might actually be on the side of the older generation.
I think both observations are missing the point that younger and older people have different experiences, and neither is inherently better.
There's nothing stopping adults from getting into the younger scene en masse except a lack of interest. They just have different things they like to do which are no more or less valid.
I'm in my mid-30s now, and I know some people who are, or at least were, really good programmers. But I was amazed recently when they didn't really know what Ruby on Rails was, or django, or AJAX. I'm not trying to play buzzword bingo here, and I certainly don't think people need to know these things in detail, or agree that they're good tools. But it is very alarming that they draw a blank. These aren't obscure technologies - if you haven't even heard of them, you clearly aren't paying attention.
I suppose the 30+ set could get insular enough that nobody brings these things up.. whereas it's nearly impossible not to learn about them if you hang with a younger crowd.
That said, I had a professor in college who was over 70. He could write programs on the whiteboard that would compile without a single syntax error - it was bizarre. He was unbelievably up-to-date. And it wasn't out of some kind of old man and the sea stubbornness, it was just deep in his personality to keep reading, hacking, knowing what's up.
You can't tell who has a drinking problem in college, because everyone drinks too much - you have to wait and see who's still overdoing it 10 years later. By the same token, maybe you can't tell who the true hackers are until they've considered and rejected the opportunity to fade away...