WotW has the exact issue. Bungie KNEW it was too OP for their sandbox, but they released it into the game anyway. They did the same thing in D1 with the exact same gun, if it was too OP back then, why the hell did they think it wasn't too OP this time? Answer is that they knew, and always planned to nerf it in the future so that they could boost player numbers, and they'll keep doing this with exotics and pinnacle weapons. Make them so good that everyone wants them and will grind for them, and then when everyone has chased the fun for a while, they nerf it...