If there is only minor changes to the UI and not Major ones for iOS's 10th anniversary, I have no more respect for Apple's design department. This is ridiculous that we were, and still are forced to use the current UI. Apple really should've gave us an option to use the new one or old one. The current one doesn't fit in with the character of the devices anymore. When I'm holding a premium glass and aluminum device, I want a UI to fit it (iOS 6). When I'm using a colorful plastic or colorful anodized aluminum device, I want a UI that fits with it (iOS 7).
When you buy a new car, you always get an interior to match the exterior color of the car. It really shouldn't be different for operating systems on devices if you think about it.
Boy, I sure do rant about design a lot don't I? I can't help it, design is something I love, and bad design (iOS 7, OS X Yosemite) gets under my skin terribly.