The wouldn't do it beacuse it redundant, pointless, and over powered. Im not saying it a bad idea just that it wouldn't work in Destiny. Its redundant and pointless becuase unlike BL, elements on guns are only for knocking out shields in PVE other than that there isn't any point to use a void, solar, or arc. Would be different if, for example, the Vex was weak to Arc and took 20% extra damage, so you would bring Arc weapons to fight against them. In PVP most the time your going to just use 2 gun anyway. BL was never a PVP based game, and PVP was grossly unbalanced. Its overpowered because it allow players to have to much verstilty in in PVP. I don't really like the idea or a player being able to use a snipe, press the d pad and have a shot gun. Or swtich to a hand cannon just because i gap closed. Its a good idea just not for Destiny.