My thought is that it's similar to the way that Blippi reincarnates certain elements of Barney (the slow speaking rate, exaggerated facial expressions, over the top enthusiasm and uber expository dialogue...) In that the features that draw in kids as viewers tend to be reproduced, because, well, they earn viewers, ergo execs like them. So yes, it's been done before, but it's all been done before for a reason.
This overall style has been around for awhile, and I suspect originates somewhere in the anime world (although I'm not a cartoon buff and couldn't say for sure). To my mind the key elements are: 1. Exaggerated, simplistic visual representations of what is happening in the plot 2. Limited need to follow a lengthy verbal narrative because most of the action is visual 3. Fast paced action, with lots of action, be it slapstick comedy or wild chase scenes or whatever the case may be. I think this connects with kids of the Youtube generation.