I don't see any evidence that the company is atrophying based on its own measures of success: stock price and market share.
That's part of the cultural problem. You can't know if your culture helps or hurts because there's no control group.
Since Google is doing well financially, they'll have to conclude that their culture is good (or good enough) and stay the course. Firing VPs is rocking the boat, and any Board would be infuriated by it.