I think the issue myself is the high contrast of the blue and grey. Its looks great in certain areas but terrible in others. Autodesk did this awhile back with 3dsmax (dark grey interface with blue buttons) it was great till the new interface feeling wore off then I switched back to the various colored buttons. that's the exact feeling I have right now.. with no way to change the preference I'm forced to revert back to an old version just to be productive and reduce eye strain. my guess is that the designer did a few items in the blue and someone said that looks awesome make it all blue.. I had this happen to me many times as a designer and its the worst thing to say ok.
hope they make an option to have the older interface colors back. I like the flat look though that can stay.