Does it really matter? Bottlecap mines are better and the resources to make them are infinite.
I think that's some of the issue, if it really worked like an "I WIN" button when you launched a Fat Man at a group of enemies it might be okay but it's WAAAAAAY underpowered on top of being super rare.
Some of the balancing the devs did on this game seem to have limited the truly viable weapon options.
It's like Guns or Guns or maybe melee/unarmed.