One of the reasons for their popularity is the preponderance for left handed leaders in our society.
Just think of politicians - in the UK, Cameron, Brown and Blair are all lefties, in the States, Obama, GB junior, Clinton, Reagan, Nixon and I may have missed a couple (Carter?).....and in the business world, a lot of finance folk are as well.
And of course Napoleon as he was the one who switched vehicles to drive on the wrong side of the road.... which hand do most of us hold the gun/sword/lance when riding?