Not much of an explanation, but plausible. I tried this in 2011/WIN7 and I did not get the Keyboard folder. It's possible this is only done in 2013 (maybe 2012?) and may have something to do with directing Maya to the project directory when people double click a file to open it instead of setting the project. I'll have to wait until I get to the office to try this in 2012/2013 to verify.
Dave Baer
Professor of Digital Arts
Digital Media Arts College
Boca Raton, Florida
dbaer@dmac.edu