Is hopping behind that wall where no adds can get to you on the final boss of this week's nightfall (Nexus) an "exploit?" Because by the simple fact that Bungie built a wall into that otherwise perfectly circular room that you can regenerate behind, pop out to put some shots on the boss, funnel the adds to you and take them out, etc. basically means to me that that's how Bungie "intended" that fight to be beaten. At the very least, they put it in as a legitimate option. If you want to take a more difficult approach, be my guest, but I think using these types of "exploits" qualifies as "working as intended."