Aero wasn't meaningless eye-candy added to Vista to distract from a lack of innovation. It was MS taking skeuomorphic design so seriously that they were willing to sacrifice a lot of performance to implement it. Aero was doomed once MS started gravitating towards flat, colorful UI's that eschew skeuomorphism, and finally decided to try to run a desktop kernel on tablet hardware.
One thing I find strange about iOS 7 is that it doesn't seem to be well suited for older hardware or budget hardware like the iPad mini or the rumored budget iPhone. Does iOS 7 perform better than this added eye candy would lead one to expect, or will it simply run in a compromised mode on weaker hardware?