A platform built on sand
I'm amazed that Google thinks Angular has any right to be considered a platform. A platform needs to be stable. Angular isn't.
You can't just made fundamental non-backward compatible changes to your platform and expect everyone to happily switch over. One of the reasons why Microsoft Windows is so dominant today (aside from the whole convicted monopolist thing), is that Microsoft cared a very great deal about backward compatibility. Heck, if you're using 32-bit Windows 7, you can still run applications that had originally been written for Windows 3.1. That is over two *decades* worth of time where compatibility was maintained.
By comparison, Angular can barely maintain compatibility across 2 years, let alone twenty. That is not the makings of a long-term viable platform. Google says they're trying to "not break anything", but time is the one and only indicator of whether they will hold true, and so far Google's reputation doesn't leave much room for optimism.