I did at least one spinning session with every one of my students. In my opinion; yes it is not easy to get most a/c to spin in the first place; a lot easier to stall though. How many of us have seen people freeze up or do exactly the wrong thing when a 'surprise stall' comes along?
Therefore i do think spinning is well worth doing in the aircraft. It is not good enough to talk about it; and then point to the stall recovery sticker on the dash and say trust me; this is how all this works. They need to see it happening in a controlled and safe way. I think the emphasis as with stalls should be to make the student realize what these things look like; and more importantly why they need to be avoided in the first place.