I'm amazed that you can look at the wreck Yahoo has become by blind optimization and say they know what they're doing.

In the particular case of Yahoo Mail, their crappiness has driven off large numbers of high-end users. They also lost a lot of great staff who were tired of working on crappy things for managers who didn't give a shit about the users or the workers as long as the numbers were good and their political power increased.

Yahoo's a classic example of what happens when you know the price of everything and the value of nothing.