Being taught "by rote" is never a good thing. Turning at 500ft taking no account of wind or circuit traffic is a poor example of teaching. As you say - if it's a strong headwind then wait. Turning early is going to give you no time downwind at all (think about it - if the headwind's that strong think of the effect going the other way).
So - yes - if you're at 500ft and you haven't reached the upwind end of the runway then leave it until you have gone past it.