I'm ambidextruous, too, but prefer the right hand for cutting since knives are usually sharpened on the left side of the blade, that is for right-hand-use.
Also, here in Europe, we use both hands. You are supposed to cut one piece and then eat it with the fork, without the knife leaving your hand. The American method is tolerated in small children and acceptable for old people. However, you are supposed to always keep both hands (to the wrist, no further) on the table.
As such customs usually have a historical background, I suppose that we eat this way because it guarantees a maximum security for the other eaters. Your hands are always in sight and you keep the knife where everyone can watch it and react to a possible attack.
I'd be very interested, though, in learning what caused the American method. Is it only spite (doing it as different as possible from the way it's done in the homecountry) or is there a practical reason (having a hand free to grab the revolver lying in your lap)?
edited to add:
Might I have that peach pie recipe, TSQ? It sounds interesting. I offer my mom's recipe for peach cake with aniseseed in return
