"For anyone who has never ridden a horse in a collected frame - how can you possibly give an opinion on something you have no experience of therefore no idea of if its useful or not?
I suspect ALL of us have ridden a horse with SOME collection. Very few have ridden a COLLECTED GAIT per the FEI.
However, it is pretty easy to notice that collection requires more work from a horse and results in it covering less ground in a given time. So if you prefer efficiency or speed, very modest levels of short duration collection are fine - and are easy to achieve.
When it is 100 deg and we're going down a rocky trail, a smooth, flat gait with minimal foot lift is better for my horse. I go jogging in those conditions regularly, and a smooth jog is more efficient that ballet would be. It is hot out, I'm wearing long sleeves and a scarf to protect myself from the sun, my horse has no shoes to protect her feet, the ground is as hard as pavement with various sized rocks on top...so why would I want a collected gait? Yet this IS the goal of my riding:
Of course, having trained her to do a collected trot wouldn't be harmful, since she (and I) could choose not to use it - but what would I want to train her for something I don't use? Why would I adopt a position that allows me to use spurs if I don't use spurs? Why would I get her used to constant contact when it doesn't offer me anything in the riding I do?
And if this is 'low level' riding, so what? We're happy. A collected gait is about as useful for what I do as teaching her to jump a fence would be. In the desert, jumping things is a good way to die.
Further, the normal balance of a horse at a walk is roughly 57/43, not 50/50. That balance is what their bodies are 'designed' to do. Of course, that figure might differ if the horse was bred with dressage in mind...but an average horse is used to moving more on the front than back.
The same is true of 'on the bit'. The FEI says, "...A horse is said to be “on the bit” when the neck is more or less raised and arched according to the stage of training and the extension or collection of the pace, accepting the bridle [emphasis added] with a light soft contact and submissiveness throughout. The head should remain in a steady position, as a rule slightly in front of the vertical, with a supple poll as the highest point of the neck, and no resistance should be offered to the rider.
So if someone doesn't WANT the horse's head in a largely vertical position, free to move about at the horse's choice, then the person does not want a horse 'on the bit' per the FEI. And given that the position of the horse's head impacts where it can focus it vision best, it is reasonable for a rider to reject putting a horse 'on the bit' - depending on the goal of their riding.
The principles of dressage are in no way "wrong". But neither are they the universal definition of proper riding and motion. They are a refinement of riding, emphasizing certain aspects that the rider wants over others that the rider does not want. It is an admirable pursuit, as is jumping, polo, barrel racing and reining, but not THE pursuit that measures all others.
"The average, 15 hand Quarter horse does NOT weigh 1200 lbs.
If one wants to create a mental picture of a somewhat short, stocky horse, what breed comes to mind? I regularly see ads for QH claiming a weight of 1200 lbs. This one is supposed to be 15.1 & 1200 lbs:
"Lithuanian Heavy Draught
" may be more accurate, but it doesn't really create a mental picture for most of us. And honestly, the picture I showed of actual armor plate on a stuffed horse doesn't show a very stocky horse, either: