The taskbar failed to switch to an app that I was using a minute ago which I didn't terminate. The taskbar acted to hide itself in various occasion that wasn't in gaming mode or slideshow or screensaver or movie mode, while I specifically set the taskbar to be always visible and on top as a default behavior since win95.
If you take your time to understand the principles, you will understand what I mean. And yes, I perfectly know it is by design, and by design, the taskbar no longer functions as expected.
Taskbar = always visible instant access to switching tasks that I am and was doing not long ago. There are ways to prioritize those tasks for me and I am open to discussion about it. But if I was using it a minute ago, I need the app to be switchable through this instant taskbar.
Try VS development while you use IE Metro to access MSDN, and then multi-tasking on metro mail, metro calendar, metro music, metro PDF reader in single monitor.