Microsoft listened to us and introduced an option to boot directly to the desktop instead of the start menu. The option for this is located under Taskbar and Navigation Properties. 

How to find it:
  • Right-click on taskbar
  • Select Properties
  • Select Navigation tab
  • Check Go to the desktop instead of Start when I sign in
Notice the other options here, you might find some of them useful!

Windows 8-1 Taskbar and Navigation