I think it was a good question. A lot of people think all work at liberty (no ropes or tack) to be NH. But you can train horses in a lot of ways, and they don't have to be particularly nice or even bother with horse mentality: because horses are EXCELLENT learners. You can beat a horse to his knees, and teach him to bow; or you can lead him the way, gradually, using cookies. All you really have to be is consistent. Horses figure out what they have to do to!
So why Natural Horsemanship? Because humans (usually) have a high regard for intelligence, for brain over brawn. Some of us get into the philosophy deeper, like spirithorse8: it does not mean he's ridiculous, just because you don't know what he's talking about.
The big differences between types of training/teaching shows up when you don't get the results you thought you would. One solution is to get another horse (not that uncommon a solution); the other is to try to think it out from the horse's point of view. "What is this horse thinking?" That, to me, is what defines NH, not working at liberty, or riding tackless.