We are not so young, and I think a lot of the ills in our industry can be attributed to characterizing us as young. It isn't that young. We know better about any number of things, and we excuse it as youthful indiscretion.
Most of the software activities we do today were laid out in the late 90's and those involved stealing a bunch of ideas from older discoveries or other industries's discoveries in the 70's and 80's. It's all old. We've just been refining execution and improving tools (painfully slowly for my tastes) for the last 20 years but it's really the same stuff.
There may be plenty of older workers but IMO, the sheer quantity of younger folks, who are told truthfully that tech is a great wage in a bad wage economy, those billion younger people globally and the youth of many successful founders and high performers, those are the main contributors to our perception as young.