I don't remember a game played by bethesda that had a stand out story and i have played morrowind, oblivion, fallout 3, skyrim. They were all about exploration and freedom about building your character. Story, dialogues, romance, strong rememberable characters was never bethesda's strong suit and if you are going into fallout 4 with huge expectations about outstanding story telling then you are going to be disappointed. Better look for bioware rpg's or witcher series if you are a svcker for strong story.
Also why one should care about how much rating it gets on metacritic? The Witcher received less rating on metacritic then The Witcher 3 but i enjoyed original much more then 3. Its not like 3 is a bad game, its exceptional but witcher was even better for its days when it was released. It had same or even better strong questlines and lots of surprises along the way, something that witcher 3 lacked. In the end, game ratings mean nothing.