1) It’s different to user expectations and doesn’t feel like an apple product.
From a designer perspective firstly the overall design feels ‘off-brand’ regarding the traditional look and feel while secondly it does seem to adhere to the user expectations due to the amount of UX changes. The fonts are too fine for readability, there’s no consistent application of gradients and colour, styles are mixed.

2) Too much relearning.
There are a lot of smaller changes to UX I will consider improvements, though looking at the bread and butter experience too many of the core features are too far removed for the previous OS. A good example of this is for killing apps, the expectation is to hold the home button then have the indication to cancel the change being is far closer to Android. For seasoned iOS users this has been a massive gripe, so where’s the X gone being the general feedback.

3) Creates too much grief on updates.
Ok, three iOS7 updates and 2 killed devices. For myself this is the biggest complaint for iOS7, the updates have turned a fair few mobile devices to iOS paperweights not due to user error rather poor patching, not enough server load for downloads and finally poor experience for feedback with why backing up and recovering is so darn important.

The other key issue being the OS yes then is a lot of animation and motion however it doesn’t add anything to the experience and for older devices absolutely kills the performance making it very slow and jittery without a clean wipe of the device, my iPhone4 was testament to this. To sum up:

• Much of the UX is poorly through out, lack of chrome and depth the interactive elements.
• It’s killing many of the older apps that are still widely used and loved.
• Too much reliance for active connection for media playback. It’s killed my iTunes library.
• Relies too much on gesture and motion effect.