Look at the stats, It's handling is high so it can be used as a finisher to enemies at low health when they run, once you get good at predicting the movement of players trying to run away it is actually okay, it can also be used at close range when you melee somebody and you don't have time to melee again because the blast radius is so small that it won't hurt/kill you or vice-versa(if you want the instant reload). In long range combat I managed to hit two guys in trials for 51 and 56 which could be headshot damage or it could be much more effective if used at long range. If you use the lunafaction boots or rally barricade it can be used to bombard a room if other players are using it too. The main way I use it is when I place it near or at an entrance and use it as a remote detonation mine. Maybe this is one of those weapons that is incredibly good once people start using it properly rather than just shooting directly at people. It's like the fatebringer(adept) is an exotic but with no exotic perks from destiny 1. Perhaps there is a reason bungie put this weapon in the game that we just don't know of.

just make it able to detonate any elemental shield.

It's fine in pve but it is complete trash in pvp. Direct hit only does 30ish damage.