It's due to openness of npm ecosystem. Any other language you'd have 50 different angulars at the same time but almost noone would know about any of them because they'd be confined to the companies that spawned them.
Frameworks as a popular thing started because people (rails?) started sharing their code and no other can share code as easily as JS and npm.
Angular 2 should be called Begular because it doesn't have anything to do with Angular but inspiration. You can stay on Angular but don't be surprised that people will prefer to develop something else since Angular folk painted themselves into a corner so hard that to make framework that sucks less they need to go back to drawing board.
Frameworks as a popular thing started because people (rails?) started sharing their code and no other can share code as easily as JS and npm.
Angular 2 should be called Begular because it doesn't have anything to do with Angular but inspiration. You can stay on Angular but don't be surprised that people will prefer to develop something else since Angular folk painted themselves into a corner so hard that to make framework that sucks less they need to go back to drawing board.