Install and launch an application - Gotta go through metro
Hit close on a fullscreen window - Metro sidebar shows up.
Doubleclick a video file, where does it take you? Metro
Need to look at pdf or image real quick, where are you going? Metro
Wanna use a one off app like Notepad or Calculator? You have to go through Metro, then right-click to pull up the bottom bar, hit All Apps and then finally find your app. Dear God.
Is that any different than Windows Vista or 7?
For media, you don't have to use Metro. When I open a video it opens MPC. When I open a picture it opens Windows Photo Viewer (not the Photos app). When I open a PDF, it opens Chrome or Foxit.
Hell, I want to use Metro but my workflow keeps me in in the desktop 95% of the time. The other 5% is just to open a program I don't have pinned. In that case, just type the application name.
You can change the default apps, just like you always have to not use Metro apps.
The Start Screen works just like the Start Menu did in terms of searching. Just start typing "notepad" rather than browsing for it.
I just downloaded and installed a program from the web, the shortcut to launch that program only exists in the Metro UI unless I either pin that to the desktop launchbar, or I add a shortcut to my desktop
Either way, you're going to lose focus of whatever was on the screen to begin with.