I agree with the issue on long pasterns vs. shorter pasterns. Long pasterns are a weakness if you plan to ride your horse any distance.
A few years ago I posted a photo of one of our horses who is half pritzlaff bred and he was VERY correct in the legs. Yet, MANY people on this forum bashed him saying he 'has short pasterns'. Personally, I don't see them as 'short' I see them as being exactly as they should be. Not short, and not long.
This stallion, I rode quite often, he was a great horse. I think horses with long pasterns might be a little softer to ride through a meadow on a sunny day
but if you were to ride this long pastern horse any distance over 100 yards, or up and down the mountains or rougher terrain, the horse with long pasterns would turn up lame. He also produced horses who were great for performance, and one colt, turned out to be an accomplished 100 mile endurance horse.
I really think that it does take someone who rides, or at least a person who understands the mechanics of a horse for the purpose of riding, endurance, speed, stamina, etc. to write the description of legs, etc, for judging quality in regards to conformation. If the pasterns are too long, they are weak, and will break down. Just like I don't like to see a horse too long in the back as they become weak in the loin and coupling area.
Long pasterns give the horse a 'cleaner and more refined' look to the legs. It adds length of leg to those horses who have a poor or short forearm. (Sadly, I can say, I see more and more horses all the time with a short forearm)I think people didn't understand a long forearm is good, and ignored that aspect, and found a way around lengthening the leg in the pastern to make up for poor forearms or a long and sloping shoulder. Their eye is seeking symmetry. Personally, I'd be more concerned about the stumpy looking horse with no forearms, than a longer pastern. But certainly, this is not the ideal horse for any sort of performance work.
I think in the end though, when a 'great' horse does come in the arena, he will stand out amoung the rest, and although some can't exactly verbalize point for point what makes a great horse, we all for the most part, have the ability to see 'symmetry' and 'balance' in a horse.
A few grey areas, but otherwise a good judging system.