It is because we can risk dying that makes self resurrecting a team use. For instance, I always stay back a bit during legions on the confluence part of hard vog. I do it so that the baddies aim at me instead of my teammates in case they have trouble getting in the cave to hide. I act as a decoy because I can come back. It also allows us to do more risky things with a bigger reward when shit hits the fan. Say I'm defending a conflux, teammate dies and we're getting swarmed. I can either retreat and risk them sacrificing or get in there, do some damage, die, come back, and do more damage.