*shrugs*
I used to watch Nick in the 90s up until A:TLA, Danny Phantom, Zoey 101,Ned's School Survival Guide, Drake n' Josh, Kappa Mikey, Shuriken School(Nicktoons Network). When those shows ended, and the next generation of shows cropped up, I was done. Those series had "heart". No heart when you're attempting witty one-liners every minute
It wasn't that I grew up, but the fact that the network stopped airing shows that appealed to me(yes I still enjoy types of shows I enjoyed at 15), I'm 23 now.
If you hadn't noticed, there are not drama's on nick. Only comedies. I liked the balance between Zoey and D&J. So Nick stops airing shows I like? I stop watching Nick. Case closed. No crying.
Same goes for disney. Enjoyed american dragon, kim possible, proud family, Lizzie McGuire, Even Stevens(clearly 2000s series), but they scratched an itch these current cookie cutter comedies didn't. Good Luck Charlie brought back some of that family aspect, where parents weren't buffoons, and I gravitated to that show. Times change, and the channel changed.
Edit: Another aspect lies in those DCtvmovies. In the 90s-early 2000s, the movies had "heart". A lot of effort put into them. Yet during the late-2000s, they became a "vehicle" for their tv series actors. High School Musical gets a pass, because they used "no-names".