I think it's ultimately about risk. Once it's able to make a profit, a huge, inefficient organization will probably continue to make the same sort of profit in the same sort of way. A smaller organization is more likely to do very well or very poorly, but investors don't want that. They're being paid to get 5% a year, not 200% some years and -50% other years.

IMO this would be one of the biggest benefits of UBI -- money coming from actual people instead of risk-averse institutional investors.