I think that one reason NH is not always given much credence by traditional persons is that they do not see how it is useful to their purposes.
They do not see how having a horse circle around you , unconnected , has any relevance to lunging for strength and building muscles to carry a bit and stay balanced and such. How having a horse stand on a pedestal has anything to do with having a horse go down a trail and cross a creek. How having a horse walk beside you wiht 6 feet of loose rope draping will be at all helpful if they have always lead the horse by holding just below the halter and never had any real issues doing such.
As long as NH is seen as an ends in itself, instead of a means to bringing the horse into better use to the human, then it will not be relevant to an awful lot of horsemen/women.
I have been stalking this thread and your post really got me to thinking about what I have experienced, so I thought I would share.
I think that as a whole, most show horse trainers are considered or lumped into the "traditional" group of horse training. But in my experience, the trainers I have worked for are the ones that introduced me to NH methods more than anyone else. I never used a flag on a horse before starting colts for a cutting horse trainer in central CA. I learned a version of "join up" from a top cow horse trainer that proved very handy for young/aloof horses. Granted in a show barn situation the NH methods seem reserved for starting the colts and then it gets melded with more traditional methods as the horses mature. But it obviously works. That is one issue I have with some
hard core NH followers, those methods can be used in conjunction with other methods. Just because you use Clinton Anderson, or whoever, it doesn't mean you have to stick to his program ONLY. If you do a little thinking and use some common sense it can be integrated into most any program.
I don't consider myself to be in one camp or the other. I use both and it seems to work well for me and the horses I ride, but of course it needs to be tweeked to the individual.
I think some of ill feelings towards NH has come from the extremists that think that NH or whatever clinician they are following at the time is the only way and if you don't follow then you are a horse abuser. Also the over marketing of products is an issue. It leaves you with the feeling of that it is about selling items rather than teaching about how to train your horse.