It's true that once you start using a high resolution display it's very difficult to revert back. Even on a small screen, text and images are so noticeably crisper that it resembles a printed page.
In a Computer World article, Mike Elgan describes the initial reaction to iOS 7 - namely the criticisms of the color palette and design choices, and puts them in the broader context of contemporary interface design.
When Apple unveiled iOS 7, some people said was a "flat" design devoid of skeuomorphism. Others said Apple copied other operating systems like Android and the Palm OS. Still others said iOS 7's bright, overly cheerful colors looked like some kind of My Little Pony theme. There's vague truth to all these claims. But the most conspicuous attribute of iOS 7 is that it's a pure creature of the super HD world. [Elgan has also written a lengthy piece dedicated to iOS 7 and Apple's new design direction].
But, as Elgan explains, high resolution screens allow designers to do more with less.
Each of us has a probably unstated tolerance for how big a screen we use for desktop, laptop, tablet and phone. For example, I personally feel cramped on a 13-in. screen laptop or smaller. 15 inches is fine. 17 inches or higher is great (although too much to carry). But I didn't feel cramped on the Chromebooks' 13-in. screen. Because the screen is higher resolution than other screens, I can see the same information and detail on a smaller screen. The same goes for phones and tablets. Super high-resolution screens enable you to do more serious reading and desktop-type work on a smaller mobile device.
In many regards, the emergence of these displays (which are only now becoming a standard) are, and will continue to be, the driving factor behind designing interfaces for PC's and mobile.