I know a few people who aren't able to play light. It does nothing for them, and if a dom would try light with no intention of going heavy, they'd use their safewords sooner than if they were in agony. (A little embellishment for the boards)
SM isn't listed as one of my main interests at this time. It may be as I learn more about the Life and continue to experiment (in safe, controlled environments, before the SSC hard-liners jump on me). I think that, for the most part, It's probably a lot of residue from society's stigmas, but I sort of see the physical aspects as being more animalistic, for lower intelligence beings. On a basic level, it doesn't take all that much to "beat somebody into submission." I have a lot more fun talking, learning about a girl until she submits of her own free will. (No, not saying I don't understand SM in a BDSM context is consensual, I'm just waiting for my brain to rewire itself.)
Not to say that I haven't considered it as a form of punishment, but at the moment anything further than a light paddling would only be done at the sub's request--yes, I'd do it for her pleasure alone, but also to find out whether it is something that I might enjoy, since I have not had the opportunity yet.