User blog comment:SafeBat/What happens after you capture a monster?/@comment-92.239.253.164-20120523181820/@comment-190.241.183.146-20120523204142

Aandrew, Killing something with violence is not the same as delicately carving it. Being a hunter does not mean you are expert on the organs of the monster, or how to carve them. It just means you can kill it.

Also, there is a limit of carves per monster, since you can not carry the whole monster alone. But the captured monsters are taken in big wagons by the guild, as seen on Unite intro. Therefore, they can use the whole monster and carve it better than you can do it alone.

But ALSO, arena quests have to get the monster from somewhere. I imagine some monsters are kept alive for Hunter training, like in 'how to train your dragon' movie.