I think a huge problem we see today with WP is people trying to push horses into a discepline they aren't bred for. Under most curcimstances, you cannot naurally make a barrel bred horse into a deep hocked, flat kneed, rocked back, pleasure loper. The really nice pleasure horses are bred for just that type of movement. I've had the priviledge to ride some amazing horses, multiple world champions in the pleasure, and they were bred to move slow, deep, and sweeping. They obviously didn't hit the ground knowing how to best use their talent, but training them was pretty straight forward. Teaching them balance helps them settle into a naturaly slow gait. Teaching collection, rounding of the back, and lifting of the shoulders, sets them into self carriage where it is conformationall comfortable for them to travel with a level head. We work for forward motion and hip engagement. The speed is absorbed by a deep, springy hock, that drives to the horse forward slowly.
Take this video for example... This guy naturally doesn't have a very big stride. Nice, two beat jog with springy hocks, but isn't covering a lot of ground. Good natural jogger. Same at the lope, flat front knee, deep hock coming under him. It will be easy to utilize his natural good movement into a great pleasure horse with some training in balance, cadence, and collection. Notice he also holds his head pretty level.
Lets compair a nice natural moving pleasure horse to one that was stuffed into the pleasure class. This mare is balanced, cadenced, and driving from her hock. She is forward and traveling uphill with a level topline calmly....Look at the bay behind her in some clips. Not balanced, choppy, and head bobbing along. This horse was not bred to move this slow comfortably. He has a big body and is probably a hunter horse mot of the time. Notice the tail wringing in irritation when asked to slow down more.
Another example...This is a great example of a finished westren rider (class incorporation flying changes in a pattern. Look how balanced this guy is. Loose reins, forward motion, nice deep hock. A horse cannot change leads like this with out being forward and balanced. This guy was bred to do this.
Once again, the biggest problem we see today is trainers trying to make a buck by forcing an animal who isn't bred conformationally or movement wise for this class. I would be happy to answer any questions on this discipline, friendly or not. Thanks for reading :]