I think there are some reasonable points about flat design here, but they're a bit lost in the noise. This is really "man shakes his fist at the wind" territory when he's railing against nearly identical Settings screens just because some of them include an action in-line.

I also feel like points about hover / active states didn't really make much sense, those always are more obvious when you can move your mouse or display an extra loading icon when "active", gradients aren't exactly a huge UI win

Also, I must say, the UX in general of apps is much more consistent now, in no small part due to this unification - surprised to see no discussion of this in a pros/cons style