I wish they would just remove the kill count and replace it with damage done to boss. Not saying this is you in particular but you can be shooting adds the entire boss fight and not even shot the boss once and at the end you feel like you did the most. It's a team effort if the person with the most kill count got the best reward it would turn into a competition instead of team play. Like when people go out of the way to kill a mob that you are about to super.