Boxing is a lot more than just punching someone. He does an okay job of punching people but is generally a pretty shitty boxer who does tons of things wrong (many of which have been mentioned; chin up hands down is breaking THE cardinal rule of boxing, the rule that my coach greeted fighters with and parted every day -- hands up chin down). That being said, his timing on his counters when he actually throws counters is good, his shot selection is occasionally decent (not always), and he has power.
That doesn't make him a good boxer, of course; he's still a shitty boxer (attacks and retreats in straight lines, rarely throws in combination, over-reliance on overhand right, head movement only when stationary and not being attacked) with a couple of good qualities, but those good qualities have carried him further than his bad qualities have hurt him, sometimes.
