[EdZ]

The question is why people tend to "steer" (the "effect")? I mean "the cause" of steering?

Because they want to "hack" the ball "long, far and straight".

A big factor, that people often think they understand but don't really 'get', is that you are always looking at 'the' plane from ABOVE - and that shift in perspective has people trying to hit the back of the ball as if the plane were verticle to the ground, which of course, it is not.

Inside out cut shots get folks to 'feel' the plane as angled to the ground, and gets that right side/shoulder moving in a much better fashion - DOWNplane - the down, out and forward of a proper impact.

All of this to get that magical right forearm to come into impact properly and not too high, as in most cases.

'See' that right forearm and its motion as a spoke in a wheel and the right elbow staying on 'its' plane and the golf swing becomes a much simpler motion.