If anime is illegal on youtube why is there much of it?

Well yeah the desclaimer does help because if you don't put a disclaimer it pretty much means that your displaying that anime as your own. Some AMVs are okay cuz yeah they are just little clips instead of the whole episode (like the "Don't Faint Sasuke") and most people create their own AMVs so that's why AMVs sorta tend to last longer than the actual anime episodes.