I think even if your handwriting is crap a fountain pen just looks better, or at least more auspicious. Horrible for lefties of course, but very nice to use if you're right-handed.
In a gradual shift toward ambidexterity, I've found that questioning society's insistence on 'right-ness' can be enlightening...
edit spellchecker : left handed scribes became left handed scones. The history of heavy baked goods in the development of human civilisation has been scandalously neglected by a blinkered academic community.
I'm not sure if that's really the cause. Furthermore in many ancient scripts the direction was quite unimportant, in some cases even reverting in each line (Boustrophedon).
Interesting take on direction of writing: http://shkrobius.livejournal.com/292987.html