Why is iOS7 so different?

So now that iOS7 has made its debut and everyone that's anyone has updated to the new software. When talking about functionality in software programming, iOS7 is a more intuitive upgrade from older versions of the iPhone.  Many of the features work more like a computer providing easier learn-ability, multitasking efficiency, and even more organized photo browsing. 

However, I cant help but question as a graphic designer, the reasons behind the completely altered interface.  The design of the icons is completely transformed and ...flatter.  Coming from a designers standpoint I was intrigued by the simpler, 2 dimensional versions of the traditionally highly detailed Apple icons.  The realistically rendered graphics of a compass, newsstand, calendar and camera etc. seemed to me as a trademark of Apple design.  So why did the development of the design seem to be reverting?  I decided to research this further and found that there is a new movement in interface design toward a simpler and cleaner aesthetic.  Instead of high digital realism the icons merely suggest a pictorial resemblance to the object represented on the app button.  Apple isn't the only company flattening its operating systems as Facebook, Microsoft, Yahoo, and Google have seen design changes in the past few months towards less dimensional design. 

Some major reasons behind this transformation include the need to increase reader legibility especially for smaller interfaces such as mobile phones.  The constraints of smartphones leaves designers with the problem of presenting a plethora of information in an organized way.  Flat design leaves a neater, less cluttered space for users to work in.  Withe less distractions and unnecessary ornamental decoration users can receive information in the most efficient way possible.  Some designers feel that this new type of clean, modern and simplistic interface design is also more sophisticated.  As this new era of interface design begins it will be interesting to note where else we will see this change in our society dominated by technology.