There's nothing wrong with letting backers have a say in the games. They don't need to direct where the story will go or how the game will be played. Backers getting a say could be as simple as, "Pick which character model you like best!" or, "Which piece of music should we use in this room?" They are choices that won't make or break the game, but that many backers would like having a hand in picking. Also, if the developers are borderline on an idea they can ask the backers what they think, like a 90k member focus group.