Because nothing based on RNG (aka luck) can be earned. It simply defies all logic. You can't earn something you got on the flip of a coin. Sure you did a few activities, but there are no set rewards for doing what you did, only a lucky handout that the game mechanics decide. A guy going afk in a Strike or the Crucible could get the same. I don't want to rain on your parade because that is a great haul but you got lucky, that's all.