Everyone has an opinion
As Harry C. Marks is so keen to point out, no one asked for my opinion (or yours for that matter) on what I think of iOS 7 and honestly, I haven't touch the new operating system in person, so I feel that I am ill-equipped to provide such an opinion. However, I can discuss the fever-pitch that occurred prior to the unveiling and the reactions after the fact since Mr. Marks is correct that everyone seems to have an opinion and love it or hate it, iOS 7 is polarizing and people want to talk about it.
The fact that people want to talk about it is a net win for Apple in my mind. Apple has always had mindshare (and profit share) if not marketshare in the smartphone and tablet space. Every time someone thinks of a smartphone interface—in both hardware and software forms—Apple is the first company they think about. Given that amount of credence, any change, especially one as giant a step as iOS 7 will be, is going to get reactions that span the gamut; for the record, I am with Mr. Marks in my sit back and wait to have an opinion until it is actually released approach, but I generally like the new look.
In addition to people's opinions about iOS 7, I am consistently reminded about that complaints about iOS 6, or iOS 5, and so on down the line. Designers, users, developers alike all have to expound on what is wrong, missing, or just badly designed, but when Notification Center was released with iOS 5 in all its linen-covered glory, designers were perturbed that the depth metaphor made no sense. Allow me to explain and then link to a better explanation on the subject: the linen backgrounds in iOS exist to show a bottom to the interface, to conform to a depth metaphor. When an iOS user brings up the multitasking tray to switch to a recently-used application, the linen is there because you are beneath the current interface. However, the linen is also there when a user pulls down Notification Center, which pulls down in front of the current interface. Designers don't like sloppy software metaphors and I, too, am annoyed by the linen idea for this reason. Follow this link for a more in-depth discussion of this topic.
In iOS 7, the linen metaphor is gone, as are most textures and illogical depth schemes. I would like to offer up as food for thought the idea shared by Gizmodo's Kelsey Campbell-Dollaghan: instead of flat (which many were expecting), we got depth. But I want to take that idea a step further because instead of just a depth metaphor of a linen background underneath an interface, we instead received logical (almost physical) interface depth, which is exactly something that I would expect from an industrial designer like Jony Ive. Parallax software design and the nature of transparent user interfaces of the past aside, the transparency that Apple is using in the new Control Center (Video) and Notification Center (Video) interfaces forced them to stay honest to the notion of depth, as everything 'beneath' an interface is blurred but not blocked from view. I welcome these types of changes that attempt to bring clarity to an interface through transparency (both in design and communication of intention).
In addition to the fixed metaphors, there are many updated features and UIs on which onlookers could be focusing, including a few really interesting sharing and background features for developers; instead, they choose to spend their time rethinking an interface they have yet to see in person or use, an interface that may not be set in stone in some of their areas of complaint. Perhaps Apple is listening to complaints, perhaps not, but in the end, I think the net gain is in seeing an interface that is fresh that Apple can use to grow into the future.