"Why? It shows intelligence. Why sacrifice itself, if it isn't necessary? They do it when there's no other choice and are already as good as dead. If they're still very much alive and have all their equipment, why would they want to commit suicide to achieve the same result?"
because the predators have an established code of honor, if they can't win, or are in an unwinable situation, you scarifice yourself, thats how they roll, AVP pretty much shat on that completely, predator using the bomb as a weapon in combat, they might as well have just all gone in, dropped their bombs from the start, and left if it was that easy, and if the bombs were counted as another part of their arsenol.
but no, they are last resort, when they've lost, and don't plan on winning, self destruct mechanisms
truthfully, even if Scar had survived the whole ordeal, he shouldn't have been treated with any respect at all.
and don't get me started on the team up, please don't