I once included Google's V8 engine on a project I was working on. Google would regularly make breaking changes with no documentation. Developers were required to figure out the new interface on their own... occasionally you would find someone else on a forum somewhere who had reverse engineered it, saving you the time.
Sure, Google can do whatever they want. They have no obligation to people using their open-source projects. But he result is that many developers will be reluctant to use those projects in the future.