Right Masha has nothing to lose; she can try a new coach for important tournaments. 

I mean she needs someone who knows exactly what to do during a final and what preparation she needs for a Grand Slam. 

Masha's victories are in her hands. 

For example at the last final: 

Masha’s frustration started to show—a sharp bang of the court with her racket as she fired one more in a growing tally of errors—but her solution was to hit the ball even harder. Sometimes it worked, but often it did not.

 I would like to say that Miami tournament for Masha was not totally bad, she defeated many strong tennis players who had strong coaches But I think that Masha has not enough endurance to win a final. When you have not enough endurance, you becomes nervous easily and you make plenty of mistakes or you can't control yourself because you want the match to end quickly. 

Maria has climbed to the No2 position in the world, has been in the Finals in 2 of the last 3 Major events, and currently has 3 consequitive Finals appearances (AO 2012) Indian Wells and Miami...

and people want her to change her coach....because, lets face it... she is doing so badly....

Human Logic...!