"A camel is a horse designed by committee" is a popular cliche, and it's true. Committees are a mixture of visions, and you often get the worst of both worlds.
For a startup, losing time is death. You're often choosing between option A and option B, and neither will kill the company, but you end up arguing about it forever. If one single person doesn't have the authority to say, "We've argued enough, and now we're doing A," then you'll lose valuable time and die.
