Good article:
IMPERFECTION IN ANIMATION by Tom Gasek -
http://www.stopmotionworks.com/articles/imperftanim.htm
Written with reference mainly to traditional stop-motion animation vs. CG , but the points are equally valid for hand-drawn vs. CG.
In the constant push to learn new software there develops this illusion in many beginning student's minds that the software is what will really do it for them, that's what is really important. They lose sight of animation as an expressive art , that shows the hand of the artist.
(click the image to see image larger)
(*some might say that the high-standard set by animators like Milt Kahl, is "perfection" in animation , but it's a skillful illusion-of-perfection, the "illusion of life" , not a slavish reproduction of realism , because there is enough artistic license and graphic "cheats" in these drawings to keep them from looking too perfect, too realistic. The human hand of the artist is evident. There is a warmth and appeal to the drawings that we respond to as humans.)
This is in no way to denigrate the skill level it takes to do appealing, warm CG animation. If anything the CG animator has the greater task to avoid having the animation look "too perfect".