AngularUI is confusing, mostly undocumented and often behind Angular. Splitting ngRoute/ngAnimate into their own files is an odd choice, although I assume the former is so they can replace it with the superior ui-router. Which also is weird. Like jQuery, it seems like the UI portion is just off on their own doing what they want.
Google has the chance to build the new framework that will run the web in 2-3 years. Much like Rails a few years ago. Angular is an amazing framework. It seems like they just don't care.
Angular needs someone versed in developer usability to take control of the public facing Angular stuff and give it a complete overhaul. Right now, it's the result of hundreds of people haphazardly making changes.