"Nothing wrong with that. As long as you know the difference between succeeding at something you're good at, and succeeding at doing something for the wrong reasons." Or something like that. Basically, Piccolo saw no reason not to like being good at something. Just as long as that something didn't hurt others without justification.

After all, Piccolo loved the thrill of the fight. He had a warrior's heart. But he would never want to hurt anyone who didn't also enjoy the battle, or anyone that didn't deserve it for some reason.