It is too dangerous, that should be enough. The way everyone is positioned on the court in normal play if you have someone throwing from the left everyone would have to move to the wood so not to get hit. It ruins the natural flow of the game. If a player throws a sidearm with his right hand then the players move in toward the wall to catch it. If that same shot is thrown with the player wearing the cesta on his left hand all the layers must clear out towards the wood then come back once he has thrown the ball. It would be ridiculous. It may even be a rule but Ive been playing jai alai quite a long time and I have yet to ever see an official rule book.
