I did the right side, it seems only fair to do left, too.
Left always gets a bad rap. Being left handed was thought to be either a fake or evil—a friend once told me how her left-hand using mother was forced to write right handed by her teachers. It probably doesn’t help matters that a Latin word for left is "sinister". Then in English, right is a homograph for a word meaning correct, while left is one for remainder.
This prejudice goes back a long way. Left comes from the Old English word lyft, which means weak or foolish. In the thirteenth century, people starting using it as the term for the opposite of right, and they chose that particular word because of the “evil” associated with that side. Really.
These days it seems silly, but left-prejudice has existed since long before the word existed. At least part of it is due to the belief that the devil is left handed, but I think most of it comes from the oldest prejudice in the book: majority versus minority. It’s different from most everything else, so it’s weird. Which explains why lefty prejudice was common across different cultures and religions.
As for the leave sense of the word, it’s actually coincidence, not left handed prejudice. It’s from the Old English laefan, and because it sounds funny to say “levt” or “leaved,” (which is actually a word with yet another meaning), it became left.
Sometimes a homograph is just a homograph.
The Online Etymology Dictionary as always.
Molly Kalafut’s paper on left-handedness
Time Magazine’s article on left-handedness