Why Doesn't Windows 8 Just Look Like THIS?

In the interest of stirring up trouble to no good end, I present a fairly obvious and uninspiring idea for how the desktop should look in Windows 8. That is, yes, please, give us a full-screen Metro-style Start screen with its full-screen apps, and make that the default on tablets and other small devices. But why can't the Windows desktop really be "no compromises" for those of us with big screens and powerful desktop PCs? That is, why can't we run traditional Windows applications and Metro-style apps, but in this environment as floating windows, side by side?

No, seriously. Why not?

It could look something like this.

Nothing dramatic, nothing world-beating. Just pragmatic, and doable, and entirely in keeping with the Windows team's "no compromises" slogan. That's what a no compromises version of Windows would really look like.

Why aren't we getting this?

Update: Far too many people have misunderstood this post. Allow me to clarify. I'm not suggesting that Microsoft should abandon it's Start Screen/Metro stuff. That's ludicrous. What I'm saying is that Windows 8 will have a Start screen and a desktop. And that the desktop will still be the primary UI for people on desktop computers with large displays. Given that, why not bring some Metro goodness to the desktop? Was this really not obvious?