I think 8.1 and later fixed a lot of this, but in 8, even if you were on a 100% "desktop" device using mouse and keyboard, whenever you'd "close" an app, it would take to the huge start screen instead of your desktop, and you'd have to find the "desktop" button to get back to that.

This is some of what I wrote in July 2013 as suggestions for how Windows 8 should change behavior when mouse and keyboard is present:

• By default, boot to the desktop. (This is a new individually available option in Windows 8.1.)

• By default, return to previous applications. Similar to Windows Phone and Windows 7, when you close an application, you should return to where you were before. If you are in any kind of desktop experience when launching an application, whether it's for the desktop or in the Modern interface, you should return to that desktop environment upon closing the application.

• By default, open media files and documents in desktop applications. Fortunately, when you select these as your defaults, you are properly returned to the desktop when you close the application. Unfortunately, any Modern applications return you to the Start Screen when you close them.

• By default, if there is no touch screen, disable hot corners and edges. Provide an option to enable them within your mouse-driven experience.

• By default, if there is no touch screen, provide a classic Start Menu in addition to the Start Screen. Mice are well-suited to smaller menus that pop out and allow you to remain largely in the desktop experience while you select new files and applications to open. Provide an option to disable the Start Menu and jump to the Start Screen if desired.

• Upon first run and selection of the mouse-driven experience, run a video demonstration introducing users to the Modern interface, Start Screen, hot corners, gestures, charms, Windows Store and Modern applications, focused on how to access these items with a mouse and keyboard.

• By default, provide a Search experience tailored to the desktop environment.

"Most of the above options already exist in Windows 8, but it takes some information, time and effort for users to change the settings and get the experience you expect when using a system without a touch screen, largely driven by mouse control. It is in these conditions that users are frustrated by Windows 8, as they find themselves faced with interfaces that are much friendlier to touch screens, and are unexpectedly removed from the desktop experience and placed into the Modern interface and Start Screen, disrupting their workflow and adding extra steps to return to the windows, applications and tasks they were working in. An overall one-click default upon first usage of Windows would allow users to select the mouse-driven experience they prefer on systems that are not primarily driven by touch."