People are in denial about just how overused it is - and while in this case overused doesn't mean overpowered (it's not the best PvE weapon for DPS for instance), it's overused because of how effective it is for multiple roles and how accessible the ammo is in Gambit (drops from orange bar enemies and also has ammo pick-ups by the bank). Boss damage, killing adds, and it one shots a Guardian with overshields even on a body shot from long-range which is very, very easy to do at very little risk given how far back you can take people out with it. Compared with other one-shot kills... Shotguns have a larger risk factor of getting up close. Snipers require a headshot and are extremely prone to flinching. Haven't seen anyone using a regular Fusion Rifle while invading. Linear Fusion Rifles (the legendary ones) require a headshot and don't have the same level of zoom as a sniper. Rocket Launchers can be avoided at range, and tracking can be broken by Hunter dodge or even hit an obstacle while trying to track. Grenade Launchers require near/direct hits. In summation: low risk, high reward weapon that doesn't require much talent to use, also functions amazingly for boss damage. It just offers the most bang for it's buck and is advantageous to use over other power weapons and Exotic weapons unless you're using something like Tractor Cannon for utility.