Seems fairly obvious to me that there are people out there who want the desktop while others like the idea of what metro can theoretically bring to the table -- although I think most would like these apps to be available in re-sizeable windows too rather than in fixed 50%, 25% etc screen sizes.
I'm sure some of these apps will improve a lot from the rather rubbishy selection we have currently - a problem is that with Windows changing its direction nobody quite wants to spend a lot of time developing these if the whole code and API need to be changed.
Another problem is that for desktop users there's no "official" way to pin Metro apps to the desktop or add them to a cascading menu so integrating these for desktop users is a pain as a desktop user essentially has to leave the desktop environment to launch these.
A few can be put on the quick launch toolbar but that's not always a satisfactory solution - especially if you want Cascading menus.
Anyway by using Custom toolbars in Windows 8.1 I've managed to create a cascading menu containing a mix of standard and metro applications and also I've shown how to pin these to the desktop. No 3rd party apps or registry hacks are needed and the toolbar can be saved as a file so you don't have to re-create again if you re-install windows or get a new computer.
If Windows 9 DOES bring back the classic menu again then I hope it WILL incorporate Metro and non Metro apps as I've done on the custom toolbar.
For screenshots and how this is done please read my thread on W8 Forum