I believe Microsoft programmed this on purpose because they believed if you are in the desktop mode, you must be using a keyboard and mouse because the desktop mode is unfriendly is touch screens. If user is using a standard x86/圆4 app from the desktop in 'desktop mode', the keyboard will not pop-up automatically. In Windows 8/8.1, the only was for the on-screen keyboard to automatically pop-up when the user taps on a field (like the URL field in IE) is in a Metro/Modern UI application. Though this post is old, I decided in case others were reading they would understand the issue.
I most definitely did not misunderstand him.