If you're familiar with the political infighting between Brain, Deepmind, and subteams within Brain, you'd know there was a lot of room for improvement.
Also Google would benefit from being able to use and build off more open source stuff. Tensorflow losing to Torch for researchers was a pretty big blow imo.
Macro cultural trends at Google didn't help either. Stuff like not incentivizing work with longer term payoffs, and too many layers of middle management.
> Only that the tech became production-ready and the rest of the world took notice, and these researchers and engineers decided that they no longer needed Google's money since there was so much available from everyone else.
All that said this is very true and probably unavoidable.