Hm.. yeah, Yahtzee mentioned fallout once in his Bioshock review, but besides that I guess if he did play it he didn't find to to be the creme de creme of western rpgs that many, many people have, or he'd bring it up more. Although, he's stated he only plays an rpg when effect by space radiation or something or other.
Fallout 3, having played both games long after they where released and really loving them, I think the sense of humor and xx content along with the killing kids thing could've been kept in had it been isometric. I mean, nobody complained about killing kids in Warcraft 3, cause they looked like deformed hobbits, but turn it into first person, make them realistic, and bingo, you've got something that will land you an OA rating.
So, rather than get creative, Bethsda said, lets just use this as grounds for tweaking the Elder Scrolls engine and do whatever the hell we want. Apparently what they loved about the game was all the violence, so keeping that in and putting that on display prominently was the number one priority, seeing from that's what they talk most about.