Anyone who says story is more important than gameplay in a game is wrong. Even if it's just in their opinion, their opinion is wrong.
Pretty much any FPS launched nowadays has a multiplayer with no story behind it, and they seem to do pretty well (hell, to say Call of Duty's multiplayer is popular is a huge understatement). However, no-one is going to subject themselves to hours of gameplay they don't enjoy just because they have an appreciation for the story. The gameplay must be at least tolerable or you're not going to play it, no matter how magical the story is.
Pretty much any FPS launched nowadays has a multiplayer with no story behind it, and they seem to do pretty well (hell, to say Call of Duty's multiplayer is popular is a huge understatement). However, no-one is going to subject themselves to hours of gameplay they don't enjoy just because they have an appreciation for the story. The gameplay must be at least tolerable or you're not going to play it, no matter how magical the story is.