It is late on a Saturday and I have just got back from an evening with friends but felt that I had to explain how an archaic practice seems to have kept me and others alive for many years.
Let's not forget that it is the wing that stalls... not the rudder and elevator (unless you are exceptionally clumsy), so they will always offer some input.
Close to the stall, eg on final approach, when the wing is closer to the stalling angle, further aileron deflection could cause the critical angle to be exceeded and the opposite effect to that intended will be experienced... ie further wing drop leading to a dreaded spin from a stalled wing.
Alternative use of the rudder will yaw the aircraft and increase lift over the problem area.
I believe that modern designs have virtually eliminated the problem but surely students should be taught this method because we all jump into older, les forgiving aircraft at sometime which will bite the unwary pilot.
As I have said before... there are no hard and fast rules in this game... keep the aircraftwithin the envelope.