Whatever else business strategy formulation is, it is certainly not a democracy - neither should it be.
One man alone cannot build a strategy for a large organization - getting more heads into the game helps. But there comes a point where the contribution-to-headcount ratio starts falling like a rock.
This generally comes about in situations where no one is really willing to make a decision, and so the additional people added to the process are as much for blame-dilution ("...but we asked everyone !") as for idea-generation.
Just like there is a point beyond which delegation becomes abdication, there is a point beyond which getting everyone on-board becomes settling for mediocrity.