I think that's an excellent point, really. Kids today may be aware that there are many more cartoons out there that don't air on TV anymore that maybe their parents/older siblings used to watch, but they just don't care.
Having been an animation fan for as long as I've been alive, I can't relate. When I was a kid, whenever I would hear about a show I'd never seen, I'd always want to find out more about it. Until its big revival in the mid-80s, I'd never seen an episode of The Jetsons. But when I first heard about it, I started asking my parents/aunts/uncles about it because I wanted to know more about it. And I was quite annoyed no station in the area was running it.
Our CBS affiliate for the longest time never ran the Saturday morning lineup, but I still knew exactly what was on it, and it bugged the hell out of me that I had to miss out. Whenever we would go out of town, I'd never miss an opportunity to catch Muppet Babies or Garfield and Friends.
But that's me. I'm probably a large exception to the rule (most of us rabroadrs are, I suspect). Most kids today are probably perfectly content to just settle in and watch the quite limited diet of shows only produced in the last 5 years from Nick and CN.
But then, I'm sure there are the few - the future Toon Zone members - who daily curse the fact that they don't get Boomerang and that Toon Disney rarely ever plays DuckTales or classic Mickey shorts. But at least today's pre-pubescent animation fans have access to DVDs and the Internet. That's something, anyway.