There should be player trading because players get items by luck but the good players might not get anything good so when their friends are doing crota they aren't happy because they are to low of a level, also player trading would help the game out by making players want to play more to get a duplicate of there other guns so they can trade for other weapons. EXAMPLE(let's say I want a black hammer, and my friend has 2 but my friend wants the ice breaker and I have 4 of them well I could trade one of my ice breakers for his extra.)so at the end bungie makes more money and every one will be happy. P.s. it's also the same with armor