I think you’re touching on an issue with the democratization of horsemanship. You don’t make an ordeal out of groundwork or blow up at your horses, but by your own admission you spent your teen years riding dressage. Presumably then, you got a good education (or at least a grounding in) the concepts of timing, release, and feel. Most other English riders I have known have also gotten a feel for at least the basics of those concepts. There’s still the last gasps of institutional equestrian education alive in barns that can afford to maintain a lesson string and a series of instructors that can progress a rider from up/down lessons to 2’6" or (if you’re lucky) 3’ hunters or jumpers.
By contrast – and this is not meant to be a representative sample at all, just qualitative observations – most of the western riders I’ve known have not had that same thorough background. Some came to horses later in life; some took up/down lessons as a kid, but their families ran out of time or money. Regardless, they tended to turn to the popular tele-instructors. They could buy a prepackaged course and be introduced to the same concepts – broken into convenient, easy to digest chunks – that you and I learned in riding schools as kids. For far cheaper than a year’s worth of weekly lessons.
But we all know that there’s a problem with that. You can’t learn timing and feel just from watching a video. If you’re new to riding and you’ve never had a chance to learn just how light your aids can get, you’ll never be able to refine them to that point. Your finished aids are going to be comparatively loud, and your starting point is going to be even louder. If you’ve got a problem to fix, and you’re used to operating on a scale of “scream” to “talk,” you’re going to be more likely to start at “scream,” even if starting at “talk” will do. And you probably won’t ever get to “whisper.”
I have known a number of wonderful western riders; I’m not trying to tar and feather everyone who rides in a western saddle. However, these men and women have either come from an English riding school background (as close to a formal, institutional background as you’ll easily get these days), or they’ve learned their craft from their family (the quintessential informal system of education). But there’s a part of American culture that promotes western riding as something for the everyman, and I think that’s the root cause of the concept of manners as something that youhave to be constantly, deliberately, and loudly schooling. The Average Joe who buys a cheap horse and a cheap saddle and doesn’t want to fuss with formal riding education is going to see behavior as the easiest thing to control. To his benefit, usually, as he generally doesn’t have the ability to ride a horse with a bit of chutzpah. But at the same time, it feeds into a culture where we both erroneously equinize human behavior and anthropomorphize equine behavior, and where we see manners as a whole, discrete unit, instead of a piece of the horse training puzzle. It becomes a thought terminating cliche. Or worse, it colors your whole set of interactions with these animals.