Heh, the Gatling lasers damage is fine in my opinion, it's a dps weapon not a dam dealer, 9?240=2160 damage a clip, and it's meant for lightly armored enemies.
The fat man they over nerfed, it's damage was a bit much in FO3, due to the amount of ammo around. In NV, they are EXTREMELY hard to come by unless you know where you're going, so it's a little sad the damage is so low (almost equivalent to c4)