I wouldnt be so quick to say he's lazy I know of an appaloosa who was labeled lazy, stuborn. Turns out she needed work done on teeth. Her hoofs were a mess after all that was fixed she's a diffrent horse now.
Do you know for a fact his feet are in good shape? Is your farrier as good as you think? Do you reconise under run heels or any other hoof issue ? Because if you don't you need to do some studying of hoofs. Good place to start is barefoothorse.com.
Iv owned appaloosas and not one I owned was lazy or stuborn they are very smart and willing.
Our farrier is great. I have been around horses for 11 years so I can recognize different hoof issues. His feet look great, and he had a tooth floated earlier this year.
He can be extremely lazy, but will work hard for you as well, you just have to make him. But he is most contented when napping in the pasture. He IS extremely smart, but that doesn't change that he is stubborn. He tries to be the boss, so you just have to knock him down a peg. Again, I love this horse to pieces, but he is real challenge some days, just ironically not today. Today he was an absolute dream, but then again I hadn't worked him since Tuesday so he had some pent up energy I suppose.