1. You start a 'democratic' company 2. You make a controversial decision or series of decisions 3. You lose 'voted out' 4. Turns out your controversial decision would've been [firing a few employees/getting acquired/insert unpopular thing here] to keep the company afloat, and everything goes belly up

It's the same reason unions only work in the biggest, most established companies. Everything slows to a crawl otherwise.