I don't think there's an explanation to figure out how rng works, it's random generated, it seems it's good or bad to you but it just is, it can't be fixed because that's how it works, if people got all the drops they want, you would have all items in the game in two days, think about it, I'm used to really difficult rngs, destiny's rng is a walk in the clouds, missions are easy and you can complete them several times, in other games you complete really difficult missions and you get garbage, people don't complain there because they are not cod players, they know how rng works, here, of course all cod kids who don't know what rng is will cry and cry and cry until mom buys them another game....