User blog comment:Supermorff/Angry Joe interview for YJ: Legacy/@comment-432124-20120618030701/@comment-5145408-20120619042404

While I agree that the time skip does not let us see the heroes grow up to show the things that you state (how nightwing matured to become a leader, etc). I think the difference here is that the writers/producers are choosing to show other aspects of how they are growing up than the aspects you mention. They still have growing up to do (even at their +5 ages) so the stories they want to tell are about the growing up that they have yet to do at the higher age.

Plus, even that stated reason aside, they probably have a bunch of other reasons that they needed or wanted to do the time skip (getting to show case new characters, or allow time to pass for a plot to develop that would otherwise be too slow or mundane to pass in a day-to-day pace that is there between episodes, etc).

Anyway, that's my take on it.