> I get to do 2 clicks if I use a mouse or windows key + start typing
You can do the same thing in Windows 7 (Windows key + start typing, or click on "Start" button and start typing), plus you have the organization of nested menus.
For items you use often, you can pin them to the menu instead of digging through "All Programs".
The start screen isn't an improvement in any way for desktop users. It is better for touch screens since the icons are larger and easier to click.
>especially ability to pin apps to a monitor.
Pinning apps to a monitor has nothing to do with start screen vs start menu. There's no reason that functionality couldn't be added to normal desktop windows ("always start this app on monitor x, fullscreen/windowed"), and in fact by default Windows 7 will remember where you last had an app and restore it to that monitor (not always correctly, but it tries).
The Metro interface is not only less functional for keyboard and mouse users, but confusing as well. There's no obvious way to close a Metro app, and swiping from the top is hard to do with a mouse. Alt-F4 works, but non-techie users don't know that. There's also no obvious way to shut down the computer! Swiping from the right is non-obvious and again, hard to do with a mouse. Remembering a keyboard shortcut (Win+C) is difficult for "normal" people. Yes, they could press the power button (on supported hardware), but decades of telling people to always shut down via software have made them nervous about that.
I've had a Windows 8 laptop at home for about 1.5 years now. Once I learned Win+C and Win+X, and customized the start menu a bit, it was fine. But I'm a computer person; all the "normal" people I know hate it and just want XP back (or something that looks like XP).