Mark.... I paddle to my backside because that puts the paddle on the same side as my forward foot.
I often move my left foot forward on the board, but even when I don't, I lean forward on my left foot.
Why this matters to me.....
I stack my hands MUCH more efficiently, while paddling on the same side as my front foot.
When I paddle right sided, I "row" more, because it is harder to stack my hands over the right side of the board.
The weak angle of the paddle shaft translates to much less power
I paddle on my left side when surfing rights as well.... makes for some interesting paddle switches on late takeoffs
I try to never switch sides as I paddle for a wave, I simply "time" my turn to put my board on the desired angle, at takeoff