I think it's matter of crowd mind.
since fo3 is well sold, many people(possibly fanboys) though themselves is major so, their critic is always right and other minor group's opinion is wrong. to prove themselves are right, they need something like bible(ex:fo3, skyrim etc). but actually, they are not a fan. if they are a true fan, they can try older game to find out how this game have been improved(or degenerated) or accept criticize of game and critical thinking about his favorite game.
but fanboy don't. what they did is just like worshipping something not like loving something.