Another problem with it is that it's extremely trendy. Bright, almost fluorescent colors, ridiculous amounts of whitespace almost to a fault, long shadows, arbitrary grids for icons, etc.
The bigger problem is that Google decided to become smartasses about creating a new design language. They took it way too seriously and I think who this hurts the most is the developers who make apps for Android. They don't know what Material Design means -- really means, as in how Google sees it. Third party developers will never really be able to adapt it properly and what you're going to end up with is a whole new type of visual fragmentation in Android.
This look already looks dated, and I can't imagine what it will look like in a year.
[1] http://www.google.com/design/spec/material-design/introducti...