Why do people want to use a different oil for the first minuets of a motors life?

I have been racing using two stroke motors for many years, from club level up to Works team level, and we never used any different oil for the first few minutes of an engines life. In fact if we changed oil at any time, we would totally strip the fuel system and carbs to flush out the old oil before ever adding a new one, especially going from a natural to a sythetic based oil.

I have heard that its to allow the rings and bearings to "bed in", but in reality the revs we run these motors at ring fit is far more important than bedding in.

The wear on the piston in the first few seconds of an engines life is greater than it will for most the remainder. So why is it recomended we sarifice wear on the piston, to get the rings to bed in that bit faster.

Is it to get the bedding in process over with that bit faster, or is there a real reason?

Peter