This is the sound of thousands of hipsters realizing they won't be using the latest and greatest toy anymore. There is a shinier newer toy coming around the corner.
That is the only explanation I can come up with. Scouring the comments filled with hate and vitriol I couldn't find much substance as to exactly why the are upset. There is no indication Google is going to sue them for patent infringement for using AngularJS, they are not closing the project. It is open source, if they love and think it is great, they are free to fork it and contribute to it.