TbH, I don't think the Nightfall was really designed with much care and balancing. I think it was just a hardcore thingy made to fill some gaps in end game play, just a thing developers went crazy with to give it a "hardcore feel". Kind of reminds me of some games with an "extreme mode", sometimes shit gets so hard you just can't do anything but make use of the game itself to win. Ever tried CoD 4 on hardest difficulty ? Shit was sometimes -blam!-ing impossble, it was painfully obvious there was no balancing or anything, just some damage values changed without care about particular situations where you just HAVE to take some damage to get to destination, and that damage gets you every single time. That's the feeling I get from soloing Nexus on Nightfall for example, this week was especially excruciating. I don't think it's an exploit to use the map to hide from a boss who throws hell storms non stop at your face. Doesn't mean I accept using the map to kill Atheon, he is not hard to kill when you are not retarded, you can get him without making him fall. Try killing the Nexus on Nightfall while running around it in circle like the level design wants you to.