The first baitcasters were made right hand reel, since most folks are right handed, and casting,pitching and flipping were not a popular way to fish. Most of it was trolling or still fishing. Remember, no free spool, magnetic brake, etc. The first really popular spinning reels were European imports, a la the Mitchell 300. On continental europe, France for example, the left hand is used more. It is the proper hand for a fork at dinner, unlike the heathens in England or the US, who hold the fork in the right hand. Consequently, a left hand reel is culturally atune to the fisherman.