For instance Backbone is pretty much what would happen (give or take) if all the JavaScript books on how to program OOP and MV* got together and build a JS framework. It's not fancy, it's not "magic", but it is very approachable in terms of advanced standard/best/popular JavaScript programming practices.
AngularJS left all that stuff behind and built their own little world. It might even be a great world, but on the surface or to the implementation-level developer has little to do with "regular" advanced JavaScript programming techniques/patterns.
To me it's a bit like the JavaScript version of Drupal, which gives you a ton out of the box, but is just it's own whole world of conventions etc, that has little do with anything seen outside of itself.