Board Thread:General Discussion/@comment-5205908-20130218114748/@comment-4928331-20130218115439

It hasn't been canceled. Cancellation means it's ongoing, and the network pulls the plug.

It just hasn't been renewed.

As for why, people speculate Cartoon Network wishes to go for comedy at the moment. Plus they already have DC Nation replacements in the form of a new 3D Batman show, and comedic episodes of Teen Titans.