In order to do enough damage, you have to get way too close to any enemy you want to kill with it. I have experimented from time to time, and use Patrols to rank them up, but they are just plain impractical. They need a range buff before they could really be effective in PVE. And in typical Bungie fashion, they are going to do the exact opposite of what would make them work in PVE. They are going to give a slight boost t DPS, with a reduction in range. So to kill anything, you will need to be maybe 1m away from your target.