Could we not? I mean have you played Borderlands 2? the trading system broke and everyone had legendaries and pearls. Some people including myself farmed for hours and went into someones game and emptied the inventory and dashboarded and did that all day cause we ran outta things to do. A trading system will break the game and leave it unbalanced because everyone will have the gear they need and their will be no point on playing because everything will melt like butter before you because you got the right gear for your build. exotics and legendaries will become a common currency and everyone will have them and the game will flail and die because it does not have as many things to take on as BL2 does and did.