Don't know why you're being downvoted, because this is exactly true. Younger naive fresh graduates are much easier to exploit (or just force to stay in the office longer) than older, experienced people. That is why younger people are preferred.
I agree, I'm also 39. Force isn't obvious and actions are aimed at compliance which demonstrates perceived value. I've never seen myself as being on a "career path", everything in my life is a moving target. Engaged in a company's problems isn't why I woke up this morning.
