Because they just launched their very own
Here's a promo:
On the program:
It already on Disney XD. It will be Marvel's own dedicated cartoon programming block.
It's basically a little segment on the channel where Ultimate Spider-Man will run alongside Avengers: Earth's Mightiest Heroes. Oh and by the fall/next year, AEMH will be "changed" as they said to (hum... canceled and replaced by) Avengers Assemble - a less plot-oriented more kid friendly take on the Avengers, with more influence from the movies carried over, an humor closer to USM (think Scott Pilgrim on high sugar doses) and a different roster of characters. Cap, Thor and Iron Man will be kept around. But Black Panther, Antman and Wasp replaced by Black Widow (on the team like in the movie) and Falcon. For, some reason...?
Oh, and of course, it will also include new animated shorts and live-action interstitials. Obviously. In case you forgot this was their very own
Edit: I might have sounded pretty negative above, but I'm actually all for it! I like the idea. Now, just make those shorts as funny and well animated as this, and you can sign me in!