Yet another example that there are now many players in their 30's doing well, but the young guns are struggling to raise their game all the way to beat the top guys.
Could it be simply that the younger guys play such a one dimensional game: hit hard, run around forehands etc that they are just too predictable. Then comes around someone like Mischa, plays differently, and is able to upset good players, at least for a short while.
That's what you get when you homogenize surfaces and aim at eliminating variety from the game: You rob players of the chance to develop unique skills and it becomes a game of attrition where those with the best resources - which includes mental capabilities - prevail. At least, usually...