and that what he did is not much crueler than hunting for sport...
OK, I gotta call you out on this statement. Why? Because it is absolutely ridiculous and exhibits a complete lack of knowledge about hunters. Ethical hunters (and most of those who pursue game animals fall into this category - say 98%) aspire to 1-shot kills. They may not achieve this standard in every instance, but even when an animal is wounded rather than killed, hunters track and complete their hunt (ie. kill their prey) as quickly as possible.
In addition, a lot of hunters who are fortunate to own land plant feed plots (White tail deer hunters), create water access for the game animals, and in the case of upland (that means "game bird" hunters, btw) hunters, actively raise chicks to adolescent stage and then release them for maintaining game populations.
Ducks Unlimited is one of the premier conservation societies in the United States, and has fought for wetland preservation/conservation for decades. Ducks Unlimited is primarily (although not exclusively) made up of duck hunters. The Federal government supports Ducks Unlimited with the postage stamps known as "Duck Stamps".
Michael Vick and his compatriots chained up dogs to truck axles pounded into the ground, in the glare of North Carolina's weather, with little or no provision for their exercise. They intentionally starved their "stable" of fighting dogs to make the dogs more aggressive in the ring. The sanitation provided to the fighting dogs was non-existant. Vick and his "friends" intentionally beat to death (with multiple blows like pounding a muzzled dog on the ground repeatedly) animals that they raised from puppy-hood or purchased as young animals. They were perverse and vicious owners of their animals, and entirely responsible for the conditions of the animals dependant on them.
When the females were no longer able to fight, they selected the "most game" females, used pliers to pull all their teeth out, without anesthesia, and then strapped them into "rape stands" for selected male fighting dogs to breed with (the females were so brutalized by their time in the ring that they would attack any male dog that attempted to mount them, thus the pulling of the teeth and the "rape stands").
Equating the systematic, brutal, intentional torture of canines with the legitimate, population-managing activities of sport hunters is a travesty. You are entirely wrong to draw this comparison, IMO.
My .02.