To be of maximum benefit to a user, a tool should maximize assistance while minimizing negative effects. With mass market technology, design decisions that affect the end user are critical and even subtle things must be taken into serious consideration. If there's a deviation from fundamentals, a product can ever so subtly go from being a great tool to being a slightly disruptive tool, maybe even encouraging less healthy behaviors...

When Steve Jobs stated in 2010, "No one is going to buy that thing", referring to larger model phones, he wasn't totally wrong. From 2007 to 2012 (Jobs passed in '11), Apple had maintained the use of the standard 3.5" screen size. The basic premise being one could reach all portions of the screen with the thumb without having to adjust the hand (ehm, iPhone 5). Thus, a phone for the masses, close to effortless to operate, something that just got the job done really well. Movie watching movies and high intensity work were not major considerations in the design process because, who the heck would do that anyway. It was, and still is of more importance to have a portable, reliable, ergonomic, and effortlessly operable device. It's pretty damn subtle, but subtle things can have major impacts.  Bring back the old school size.