You're wack. So, punish the players that spent time to acquire the weapon because others didn't. It's a quest to get the weapon for crying out loud. Boohoo,"I dont have sleeper so it should be nerfed." Makes a lot of sense, not. They should go earn like the other people that have it. Next it will be One Thousand Voices that's gets nerfed by your logic. Which is even harder to obtain. People that play Destiny 2 should feel the sense of accomplishment when getting such gear. You want something bad ass, go earn it like other skilled players. Gambit requires strategy and skill. If you not good, get off the field, sit on the bench and watch the big boys play.
The complaints aren't upon the people that have it, hell most players that have it just find that its boring to have one viable power weapon.
Also the skill gap lowers tremendously while having a gun that easy to use, pvp and pve mixed nonetheless should have an apparent skill gap.
If you play a sport (football, soccer, ping pong, etc) and have hundreds of options of equipment to choose from, are you going to choose the ones that help you win and be successful? I sure would.