Blame, blame everywhere ...
No sympathy for any developers that were relying on Google - that's weapons grade idiocy.
However, it's scary to think how an update this dramatic managed to slip out of the Chocolate factory, with it's untold ratio of genuises/lattes without at least one person saying: "Hang on, is this right ?"
Imagine how many more subtle unseen and potentially corrosive bugs have slipped thought these past months and years. And imagine the horror of some poor "app" user when their data vanishes forever.