Hmmm.......it is an interesting debate.
I was shown a spin when i trained for my PPL, and to be honest it was so bloody frightening (to a low hour student) that I didn't learn anything from it!
I would suggest that the vast majority of PPL holders tend to fly certified aircraft with very docile stall behaviour. To unintentionally stall in such an aircraft you'd have to be asleep at the yoke.....the warnings are very obvious. Getting such an aircraft to spin...even when you want it to....takes some doing.
I do think if you intend to fly slightly more sporting/non certified aircraft then some spin recovery lessons might be a good idea.
It goes without saying, if you fly aeros you should be able to recover from any spin (erect or inverted) as a matter of instinct.
On balance I think the current practice of teaching stall/spin awareness/avoidance is probably a good course of action.