If they removed the new design, iOS7 would be a really underwhelming release for users. The background downloading would clearly be the banner feature.. but aside from that?
Personally I would much rather they just removed some of the gradients and textures and instead focused on improving things like inter-app sharing, notifications, the keyboard, widgets/live tiles etc.
They would have had time to improve existing apps and work out existing inconsistencies. iOS 6 was far from perfect, and there was plenty of room for improvement without a complete redesign.