I have a different solution that nearly every other mmo has had implemented since the start - you only get loot if you or someone on your fireteam tags the monster. That way, it removes the component of afking in the cave for free drops. I have no problem with people sitting in one place killing the same mobs over and over again. It's the same as my loop on Venus while I farm spirit bloom, just less moving. My issue is with those who can sit in one place, doing nothing but making sure the game doesn't boot them for inactivity. A comparison for those of you who play WoW, afking in the cave for free loot is analogous to botting or afking through a battleground. You get the rewards for someone else's labor. In that instance, you're no longer playing the game, you're exploiting the loot mechanics.