Yes, Hollywood is creatively bankrupt ( “Deep [1] Armageddon [2] Impact [3]” anyone [4]?) and has been for some time (The Extraterrestrial Mac and Me anyone?). It's also known that animation is expensive and that animation studios have been known to do as much as possible to cut the expense down, including rotoscoping [5] (such as Tarzan [6]—heck, even Ralph Bashki's [7] notorious “Lord of the Rings [8]”) and reusing the same scenes over and over again (and this isn't just limited to cartoons—TV series have done this, notably the original Battlestar Galactica [9] and Buck Rogers [10] used the same sequences of figher ships flying past over and over again to pad out the shows, like Buck Rogers and Battlestar Galactica, because otherwise, they'd be too short).
And yet, I was still flabberghasted to learn that an episode of the classic 60s Spider-Man TV (Television) show [11] (the one with the really cool jazzy opening [12] with lyrics that anyone of my generation can recite verbatim (“Spider-man! Spider-man! Does whatever a spider can! Spins a web, any size. Catches thieves just like flies! Look out, here comes the Spider-man!”)) not only recycled a script from Rocket Robin Hood [13] nearly verbatim (I mean, they had to change some names), but easily 70% of the animation as well!
The major problem with recycling this for Spider-man is that the original script had Robin Hood explaining things to his dim-witted friend Little John, so poor old Spider-man spent half the episode talking to himself, but hey, that only added to the psychadelic craziness of this particularly bad acid trip.
[1] http://www.imdb.com/title/tt0120647/
[2] http://www.imdb.com/title/tt0120591/
[3] http://www.imdb.com/title/tt0079550/
[4] http://www.imdb.com/title/tt0118261/
[5] http://en.wikipedia.org/wiki/Rotoscope
[6] http://en.wikipedia.org/wiki/Filmation#Quality_issues
[7] http://en.wikipedia.org/wiki/Ralph_Bakshi
[8] http://www.youtube.com/watch?v=_oBvNFMt9Ic
[9] http://www.imdb.com/title/tt0076984/
[10] http://www.imdb.com/title/tt0078579/
[11] http://retrocrush.buzznet.com/archive2003/spiderman/
[12] http://youtube.com/watch?v=RKWdPN2Dr74
[13] http://en.wikipedia.org/wiki/Rocket_Robin_Hood
[14] http://youtube.com/watch?v=rGl9yYvkEbY
[15] http://youtube.com/watch?v=_PkXSoDeUG8
[16] http://youtube.com/watch?v=eRw49ggXO4Q