Proposition 1: Any instructor who is not proficient and confident in spin recovery should not be allowed to fly as P1 with (a) any pre-licence student or (b) any student at all.
As part of the instructor test a prospective FI has to demonstarte competancy in spin recovery, so at least at the beginning of their career they should have no problems with spinning.
Since the the requirement to teach fully developed spins was taken out of the syllabus, apart from teaching the incipient spin, not many FI's or students feel willing to go into it fully.
The reason that it was taken out was that far more people were being killed in spin training than in stall/spin accidents. The fact remains that with the vast majority of GA types you have to be either unlucky or incredibly ham fisted to end up spinning inadvertantly unless you are doing aeros.
How many accidents have been attributed to spinning in recent years? I cant think of any, but I certainly can remember of couple of horrible accidents due to spin training.
Any FI should of course be proficient in stall and spin avoidance, since that is what we want students and PPL do. If you teach someone to recognise the symptoms of a stall etc, then hopefully they'll never need the ability to recover from a 'real' event.
Another way of looking at is if someone is daft enough to to get into a spin turning onto final, then what is the likelyhood of them having the skill to recover sucessfully?