But that's the thing - Fallout wasn't supposed to be dark. The entire setting is firmly and blatantly tongue in cheek, starting with the very fundamental "nuclearpunk" premise.
Yes, and it should be fairly obvious by the entire UI the Pip-Boy 2000 sports. Cutesy 50's style caricatures jar with the gritty situation for humor. Fallout has always had that undercurrent of absurdism in everything that rears its head to good comical effect. One of the things that I think made the third game not quite as good is that the absurdity from the characters are downplayed quite a bit, while the visuals are played up. The presentation feels uneven.