Bountying is a way of allowing spectators to have a say in the game. If people make short term alliances and then one of them gets a bounty of say 1000 points, they are usually a target for treachery which could start a fight and change the game.
Then there's the whole bountying people just to make them a target if they are your friend and looking for a challenge.
If people think that bountying doesn't even have a use, then they shouldn't use it while those than think it has a use can use it.
Also, if you want to judge how good someone is, and you believe that bounty is to easily affected by things such as lucky kills, getting friends to bounty you and so forth, just check their Win/Loss ratio. It isn't difficult. /Records is your friend!