While I'm not an old man, I am getting older (43) and my eyesight isn't what it used to be. Many of the icons and buttons not only made the buttons over-saturated primary colors, sometimes complementary colors set next together (not a good idea in interface design, generally), but the icons inside the buttons are often small, very thin lines that are difficult to make out. The metaphors they're trying to represent also seem a bit unintuitive. The art of making intuitive icons - something that Apple pioneered with the first Macs back in the 80's - seems to have been completely lost in recent years. Instead of imagery that clearly defines the function of something it's supposed to represent, iOS7 has reduced itself to a Rorschach Test of hyper-minimalism, relying on the users' ability to play constant guessing games at the potential purpose of a button, rather than to difinitively acknowledge it and allow the user to continue on his/her way unencumbered.
When something has a function, yes, I want to know what it is. Guessing at functionality based on vague and seemingly ambiguous imagery is NOT efficient. Having slightly more detail and a less obtuse color palette does, in fact, make things easier to use.
Having been a web developer for 19 years, and striving to create intuitive interfaces, it seems to me that Apple has broken many of the interface design conventions that they, themselves, established and used for almost 3 decades and have had copied and stolen over and over again by countless other companies and organizations. When it ain't broke, leave it the hell alone! Change for change's sake is NEVER a good thing. It almost feels like when Microsoft changed their entire Office suite interface around in favor of this ridiculous new "ribbon" layout. Even though it's been around now for a couple years, I still need to occasionally hunt for functionality that I used to be able to find in seconds under the old menu bar. Same mentality. That's why I'm convinced Apple has been infiltrated by lesser minions of Microsoft.