I don't know how Nickelodeon had so many series that they dropped the ball on by cancelling way too early. Basically all those classic shows were all cancelled early (Salute Your Shorts, Hey Dude cancelled just because they didn't want to keep filming it in Arizona after the Orlando studio opened, Doug, Rugrats, Rockos Modern Life etc).
I guess a lot of 90s shows in general were like that though, or early 90s at least. There must have been a flood in programming and constantly had to make room for new shows? I don't get what the deal is.
I remember revisiting pretty much all of these shows on Youtube though. Not sure if they're still on youtube, probably not the complete series of any of these either but I found quite a bit on there from what I remember.
Still a shame that DVD releases are scant and the streaming options suck so much for older shows/movies.