At the start of the series, "the team" - as its constantly referred to - is setup to perform missions at the behest of the Justice League that are a little more below the radar. Initially we have Robin (Dick Grayson flavour), Kid Flash, an Aqualad, and Miss Martian, who is a good character shows up the lack of decent female characters once you move away from the big hitters. They quickly pick up Superboy and Artemis (who I'd never heard of) to round out the team, but as the show goes on a regular, wider roster starts to build. By the second series it's practically a full-blown Justice League series, with a huge recurring adult and teen cast.
One of the joys of Young Justice is the increasing serialisation as the show goes on - reflected in the cast as much as the storylines. Sure, episodes tend to have contained story arcs, but they're all about moving the big story forward bit by bit and I suspect the strong characterisation that makes so much of the show work would be lost on a casual viewer. And here's where we get to the first problem.
Watching this on Cartoon Network was a nightmare. New episodes dropped in seemingly randomly, the showtimes swung about depending on if it was a school holiday or not, small batches of episodes would loop over the course of a couple of weeks. We've still not had the end of Season 1 here, (although I've seen the rest, um, because) and so unless you're happy to tune in at the same time every day, unless the time has changed, or your PVR is content to stack up 5 copies of each episode, you're going to lose one of the main strengths of the show before you even get chance to see them.
The same applies to Clone Wars, actually, but at least Lucasfilm have always been good at getting them out on DVD so you can buy them and watch them in order like they're intended to be.
The second problem I think Young Justice has is it's target demographic. This is a smartly written, fantastically animated take on the DC universe. It's brave enough to take big liberties when it has to, and fond enough of it's source material to embrace the essence of it's characters even if it changes them. It may be one of my favorite "visions" of the DCU as a functioning world that makes internal sense. But I'm forty. I'm probably not the sort of person that Cartoon Network wants as a target audience. My son loves it, too, of course, but I can't help but feel that he'd also love a less complex, easier to syndicate show just as much.
So the end of Young Justice on a decent setup/cliffhanger for a third series really does feel like a loss, but at the same time one I can sort of understand. Warners Animations track record at DVD releases over here in the UK is shockingly poor, which is a shame as I'd love to add it to my collection (along with the rest of Batman/Justice League, which also isn't released) and continue to indoctrinate the younger generation with it for years to come!