Looking at this chart it's pretty obvious why current cartoons are in the state they are. The fact is just since 2010, kids networks have literally lost more than half their viewership. Between online streaming, youtube, or ipad/iphone games, kids of today just don't watch cartoons the way they used to.
As I said before, 2000-2009 seemed like the last great decade for cartoons simply because online streaming wasn't as widespread that decade as it is now, in fact it didn't start till 2008 or so. Since 2010 everything has gone down.
And you guys wonder why all cartoons on CN are comedy/parody shows now, or why Nick is rebooting TMNT with Rise immediately after the previous show ended with a more comedic approach.