As with most forms of nonhuman animal exploitation and slaughter, it comes down to human monetary gain, "tradition," comfort, pleasure or convenience--with an utter disregard for sentience and for the growing body of cognitive ethology studies showing that the individuals that people like you and hunters wantonly massacre lead relatively rich intellectual, emotional, and social lives. It takes a souless person, Tony, to reify or objectify thinking, feeling individuals to the extent that you can eradicate them like a flea infestation, murdering them, tearing apart families, and leaving fawns motherless before they're self-sufficient.