The problem is that the question of what is "superficial" and "cosmetic" is apparently quite a subjective one. To Jony Ive,
iOS 7 does some things right (Control Center, for example), in many other ways it sure seems to be throwing out a whole lot of babies with their bath water. Certain pieces of iOS 6 went way overboard with their skeuomorphism, certainly, but it seems like the powers that be at Apple didn't realize the dangers of going too far the other way.
Don't dismiss iOS 7 skeptics so quickly. I'm a graphic designer working in UI/UX day in and day out, and while I do have some aesthetic qualms that don't affect the usability of the phone (i.e. the ugly, amateurish icons), most of the things that I gripe about very much DO impact its usability. For example, the excessive whiteness of the UI is not only hard on the eyes, but much makes the phone much less suitable for use in low-light. The best example of this is the Music app; not only does all the whiteness on the "Now Playing" screen completely drown out and ruin the visual presentation of the album art (same in the Photos app), but it's just unusable while driving at night (before iOS 7, I would, naturally, leave the screen on while the phone was mounted on my dash with music or podcasts playing, but forget about that in 7). Contrast it with the "Now Playing" version of the lock screen or the new Remote app, which both not only look BEAUTIFUL (especially the latter, with the blurred out album art in the background, setting the tone with a translucent UI the one part of 7 I love), but are actually equally usable in any lighting condition.
More than that, though, this philosophy of "stripping away" is only helpful when the thing being stripped away is actually useless and cosmetic. But just because something is visually detailed doesn't mean it's merely cosmetic. When you reduce the icons to their simplest form (the wireframe ones along the bottoms of Apple apps, I mean) or replace them with text, as in the Music app and when you remove all detail from everything and your interface becomes, basically, a bunch of text on white, everything just starts to run together. The user's eyes and brain have to work harder to know what's what (to know the hierarchy of information, what's clickable and what's just text, etc.). So on the whole, the design philosophy of iOS 7 of "make everything simpler" actually makes many of the native Apple apps more complicated to use, because you have to actually think about it and read more to navigate.
Anyway, I would get more specific, but I've already rambled more than I meant to I just wanted to get a word in, because the people who don't have a problem with the look of iOS 7 tend to always assume that the complaints the rest of us have are only cosmetic and don't impact the actual usefulness of the phone, when, at least for me, quite the opposite is true. Sure, I think the icons are hideous and the colors garish but that's not what I'm talking about when I say iOS 7 has design problems. I mean that some of their choices make my phone more difficult to use in an appreciable way, for no better reason than to adhere to the latest design trend.
