I think design refers to a product of the artful, skilled execution of a plan.
Prior to public knowledge of iOS 7, only snooty design snobs cared about "skeuomorphic yuckiness" in iOS. The rest of us just used this brilliant product and loved it. I never heard anyone complain about Calendar or Notes, because if they didn't like it, they could just buy an app to replace these. But legal pads in real life are yellow and have lines for a reason: it's easier on the eyes, and on the brain (which they eyes are really metonymy for in these statements).
I also never heard anyone complain about the gray interface of Safari, nor about the shiny app tiles, nor about the gradient relief on UI buttons, nor about the UIPicker's 3D look, etc., until it became fashionable to complain about it.
They didn't complain before because all these elements were very well designed. But just like in the art world, as soon as the black-rimmed-glasses crowd decides a whitewashed canvas hanging on a white wall in a white room with white lights is the best form of art, then there will be no shortage of art critics who can't find enough wrong with everything that isn't a blank canvas.
So now all the great interface of iOS is being thrown out and replaced with white pixels, with nothing. The interface doesn't stand out anymore. It's hard or sometimes even impossible to see. I can't go into details due to NDA and the fact that I respect Apple enough to let them fix all the glaring flaws they've created by removing the design and replacing it with nothing. I needn't go into detail here, that's what bugreport.apple.com is for.
It's a beta and is subject to change.
I will say that the new text features are awesome and the design of the Mail list views and message views look great. So yeah I'll say there is some nice design work in iOS 7, in places, but you have to admit much of the design was removed on purpose. I just don't get why, since there was nothing wrong with a lot of the elements they took out.
But WHY ARE THEY DOING IT? There has to be a REASON!
I suspect it's because they want to get away from being wedded to a fixed screen resolution and size. Fonts are all vector graphics, so if the interface is nothing but fonts, it can be put on any screen size or resolution and will render correctly. This is the only technical reason I can think of why they would sacrifice having bitmaps in the UI elements.
And given the pressure that's on them from Samsung et al. to have a bigger iPhone...