It's normal for people to be nostalgic. Sure, I grew up watching cartoons that was on TV when I was a wee bit lad. I still enjoy watching them years later, even if it's pretty corny when you watch them with adult problems.
So yeah, no problem. However, it becomes a problem when people start shunning new things, soley because it's not like what it was.
Yeah, not everything that's on right now is good. I'd say a great majority stinks like a rotting skunk on the highway. But you're a fool if you think that this wasn't the case 50-60 years ago. There were lots of shitty stuff...LOTS of it. The thing is what we see from many years ago are just the good stuff, or at least stuff that was extremely popular back then.
To give a cartoon example, for each Chuck Jones cartoon there were maybe a dozen or so crappy Columbia or Terrytoons cartoons. There's a reason why we don't see those cartoons anymore and it's not because of the rights holders (okay, it is, but that's not the only reason).
So let me repeat what I wrote above: only the GOOD stuff from the past are being re-released (mostly good stuff, at least). We shun the bad stuff away like filth.
I can imagine that years from now people will be talking about "Rocko's Modern Life", "The Simpsons", "Chowder" or "Flapjack". But I kind of doubt the same will be said with "Aqua Teen Hunger Force".
Of course, some bad stuff will still be remembered years later. Look at "Scooby Doo".