Mine were too, and I specifically was told that either hand was OK. Since the kiosk indicates when good contact has been made, it's a moot point about which hand is "better". If your hands are dry after a long international flight the recommended procedure is to touch your forehead to pick up some skin oils which will enable to prints to be read more easily.

Having either hand scan is obviously optimal in that any injuries most likely are only on one hand, making the GE kiosk still usable.