I agree that the snarky comment you quoted isn't that helpful, but it's clearly an aside, tucked away in parenthesis, not his main thoughts on other platforms' aesthetics.
Fwiw, most of what I imagine you mean by the 'Apple-sphere' (Gruber, Gemmell, Marco, etc) have been generally positive about Microsoft's new design ethos. Criticisms have tended to focus on its implementation, not the design itself.
But I've been reading this stuff for so long I remember when Gruber was railing against Mac OS X for straying from Aqua and embracing brushed metal, now apparently we're not allowed to criticize iOS 7 because, unlike Mac OS X, even though that's the cited precedent they give for their argument, it's guaranteed to simply get better with no potential for mis-steps along the way.
You just get jaded by this stuff after a while.
Why did Android and Windows Phone move away from photorealistic buttons? "partly just for differentiation’s sake".
Why did Apple (eventually) do the same:
"... we’ve grown up. We don’t require hand-holding to tell us what to click or tap. Interactivity is a matter of invitation, and physical cues are only one specific type. iOS 7 is an iOS for a more mature consumer, who understands that digital surfaces are interactive, and who doesn’t want anything getting in the way of their content."
Got that, this is the way forward, it's the right thing to do, it's better than what iOS < 7 was doing, and it broadly reflects design trends in other fields like the web but we can't quite bring ourselves to admit that the competition might actually be able to hire a random interface designer that is aware of this. No, they have to accidentally stumble into a better way to do interfaces just because they were trying so hard to look different from iOS6.
This childish sophistry is SOP for Apple blogs, it's the number one reason I (someone who adopted OSX and iPods as soon as they were available) think the Apple-sphere is mentally diseased and worth distancing yourself from.