I really enjoyed this thread. Looks like I'm not as "out there" as some of the people around me like to make me believe. Not a saddle-maker but that's what I'm working towards.
I never understood the "microfitting" crowd. I buy my saddles to fit me and then I go buy the horse that fits the saddle. Or sometimes I end up with a horse worth keeping around and I'll get them a better fitting saddle. As long as the horse isn't sore, isn't trying to buck me out of the saddle and moves freely under the saddle, I consider it a reasonable fit. I should note that I buy auction horses, I'm not that picky. I don't fit the mold of the current rider market so when I find a saddle that fits me, I'm very happy.
I really like that someone pointed that rider position can have a lot to do with fit and the comfort of the horse. Some people, I'm sorry to say this, don't belong a horse. An off-balance out of shape rider can do more damage in an hour than an ill-fitting saddle will. Combine the two, leave the horse in that situation for a few months and I'll pick them up for a couple hundred at the next sale. It's also amazing what a horse will put up with when you can actually ride reasonably well. I look at photos of my first horse and saddle now and wonder how she never got tempted to throw me in the creek. Very narrow tree, huge fleece pad and stirrups sitting too far back. Rode everywhere for hours on end for close to 5 years and that horse was never lame or sore.
The trick is really to find that middle range of the horses someone rides and then find a good quality saddle that will last them 20 years.