Considering guns in FO3 were basically pea shooters, and it was easier to play through the game without using either weapons or armor, perhaps they're onto something.
It doesn't make much sense for a local power to exclusively use melee weapons, but then, it also doesn't make much sense for leather armor to stop bullets, or for people to require multiple shots to their unarmored face before their head cleanly falls off...
I had a character in FO3 that didn't use guns at all, and went around punching enemies to death while completely ignoring their pitiful attempts to kill him with bullets and energy weapons. It worked spectacularly well since during character creation, I gave him 9 strength and endurance, and 10 intelligence, and to bump them to 10 I needed only a bobblehead. I used perception and luck as dump stats, dropping them to 1, which had spectacularly little notable effect on the game (at least in the PC version, when
punching things to death). I also played through the vault beginning on an XBox 360 with the same build, where it also worked (but slightly less well since I found it harder to manually punch people - on the PC I was punching enemies in the head myself whenever I ran out of action points, or just whenever).
Of course, that gets boring after a while.
For my normal characters, the best way to kill feral ghouls was using a flaming sword, rather than guns, and super mutants were much more vulnerable to being punched in the head with Fisto! than to being shot (for some reason), so there's always been a place for melee/hand-to-hand.
I can't see an entire empire of melee users unless they've been min-maxing their stats, though.
As if NPCs can do that.