said by Hall:
Sounds like poorly-designed apps that are hard-coded to look at a location vs using something like "%USERDIR%" (not sure of exact variable name).
I agree, but these were major applications. I never had a problem doing it in XP, so I suspect it has something to do with the new name in WIN7 (maybe Vista too). I assume they were looking at %userprofile%\specific folder and hitting upon a junction point they could not deal with. In WIN8 they now renamed the document folder "My Documents", same for pictures, music, etc. which may because of the problems that were caused. I can't imagine any other reason for back-tracking to the XP names. I appreciate that for other reasons too.
For myself, I've never found a compelling reason to do it. Give me one disk drive and one partition plenty big enough and my life is simple and I am happy. Image the drive occasionally and back up your data regularly and redundantly.