I was in Yahoo long before Marissa joined. And I saw her in action for 3 years. Some of those "work from home" people were very good, and were all given exemptions to continue working from home. But the lazy ones, some who I knew to be lazy, were told to shape up.

I experienced Marissa's ire firsthand too. But despite that, I give her high marks for trying. Yahoo had been ossified long before she got there; read PG's essay on Yahoo's culture. Blaming her for Yahoo's troubles is like blaming Dönitz for Germany's loss in WW2.[1]

[1] https://en.wikipedia.org/wiki/Karl_D%C3%B6nitz