but if I was flying a normal approach and finding I needed an S turn, I might just be asking myself 'why?'
ATC spacing for example? I've been asked to make an S turn by the tower before.
The fact of the matter is that as long as the wings are unloaded, they cannot stall and without a stall a spin cannot happen. Try a decent wingover and you can have the ASI reading near enough zero at 60 degrees of bank and not even the chirp of a stall warner.
Something to remember if you need to do an S turn / get slow / have an EFATO...If you PULL on the other hand you might find yourself in trouble.