I wonder if Empress Gensho, who ruled Japan for nine years and died in 748, had something against left-handed people.
It was Gensho who decreed that kimono should be worn migi-mae (right side over the left at the front) rather than hidari-mae (left over right), as was the style until then. Now only the dead have hidari-mae kimono, so it's not done to wear one like that.
(Once when I wore a yukata the wrong way, a Japanese colleague said to me, "Are you dead?" It took me a while before I understood what he was on about.)