>>It's one of the design principles of Metro... err... Modern UI .. errr.. Windows Store Apps
>>
>>>no overlapping windows ? Whats the reason for that ?
>
>But whats the reason for the design principle ?
>
>The old comparison would have been your physical desktop where you may have several things on it at the same time and if you wanted to put open more thing on your desk you would just put it on top of something else.

It may sound weird, but increasingly I've seen a trend of users preferring to maximize all application windows (then switch by clicking on icon on taskbar) rather than using overlapping windows and switching by clicking between the windows. Can't tell you the number of times I've had a user freak out because I'd opened more than one Windows Explorer window (they acted as if I was going to break Windows by doing that -- and on one or two occasions it was the IT person! ).