@730zLBGORILA By only requiring XP, it also rewards people for actually playing the objective instead of those camping on the edges.
As soon as you get kill requirements (like the assignments in BFV) you get people concentrating on getting kills and ignoring what they need to do to win the game. Would be much better to say X amount of experience and X number of objectives.
Even with your proposal, eventually everyone will get X amount of kills, just like with experience, so apart from the very start, that sort of ranking system just means they play a lot. A little bit like the old COD camo for headshots on weapons. Everyone will get lucky and get the amount eventually, it doesn't mean they are a good shot.