I think the biggest problem with most people and bitting or overbitting is pure lack of education; it's easier to listen to your peers, when they give "advice" rather than search it out for yourself and decide what is best for you and your particular horse. And most people aren't going to listen to someone that they don't know, as a general rule; sure you can offer suggestions, and even 'prove it' with your own horse's well trained responses, but that doesn't mean they will respect that...most people have to have the poop hit the ceiling, and be at their 'worst' to take advice that seemed poor at first. Even myself, at one point, just automatically trained a horse in a snaffle, then graduated to a curb, and some of those horses only responded to the curb later on...now I train and ride in a snaffle (or rope halter), and use the curb for showing mainly.
It was interesting, because last night I was watching some of the final's rodeo on tv, and almost every single horse was in a snaffle bit...not curbs like you normally see...I think that may make a big difference in how some people veiw snaffles, especially western riders, because the curb bit is the 'norm'.
"The ideal horseman has the courage of a lion, the patience of a saint, and the hands of a woman..."