While the icons in iOS 7 have already gained a reputation for being ugly and awkward, this is the first explanation for exactly why that is:
But whether we accept the idea of a grid or not, here’s the bigger point: no icon designer I’ve asked thinks Ive’s grid is helpful. In that sense, it’swrong. The large circle is too big. Many apps in iOS 7 use it: all the Store apps, Safari, Messages, Photos… In all these icons, the big shape in the center is simply too big. Every icon designer I’ve asked would instead draw something like the icon on the right. To our eyes—and we get paid to have good ones, we’re told—this is more correct.
The full post is worth a read, as it offers some of the most insightful thoughts from a well-regarded designer that I have seen in regards to iOS 7. For those interested in this topic, When Wrong Does Not Apply by R.E. Warner serves as an excellent rebuttal.