I'm semi active on Codex, and every game that gets shredded are usually my favorites.
When I see the shred, I put up my banner of protest once or twice, go buy the game and usually have the time of my life.
TL;DR RPGCodex hates a lot of awesome games
What you feel about the game is of course based on expectations. They have theirs on the game, and if one expects this to play as the 1998 Fallout 2, then that person will be dissapointed in this. My expectations was a Morrowind style game, and it's a blast to play as such a game.
I still would have wanted more options in the dialogue, more non violent approaches to quests, and less super mutants/ghouls, but it's still a very good game, based on my expectations.
And if it hadn't been called Fallout, and hadn't been made by Bethesda but by someone like Piranha Byters, the game would have had a much easier time with some of the audience, who would have celebrated the rewarding exploration and joked about the charming jank.