Team bonding. They need team bonding. Since the Avengers Initiative was canceled on SHIELD's end, they need to find some other excuse to assemble unofficially. And then party. Or something. IDK I just want them to have fun and all be bros. And possibly all sleep together, because I walked out of the movie shipping everything and everyone.

AIM really are. But they're fun and handy. They don't need reasons, which makes them perfect stock villains.