I am a huge fan of keeping a horse barefoot. If they are perfectly sound without shoes, there is no reason to pay the extra expense. My horse, however, has to be shod. He had a laminitic episode last month, so I had his feet x-ray'd and found out that he actually has very thin soles. A week later, I had shoes, pads, and Equi-Pak fill put on his fronts. Now, he is 110% sound, more than he ever was when he was barefoot.
My point is, if a horse is sound barefoot, they aren't gimping around, or having issues with their stride, they don't need shoes. If shoes can help alleviate a soundness or conformation issue, they might be necessary. It depends solely on the horse in question.
"A rider who would trade partnership for obedience
will have to settle for neither."