Actually they do because that's how it always works. Communes or collectives or whatever term you may wish to use always work with organizing committees - which is invariable the state at the top level. It in turn always has a leader - a Stalin or a Mao or a Castro or a Pol Pot or a Ho Chi Minh. Some are more benevolent than others, and some more powerful - virtual dictators aren't uncommon.
All organizations have a leader. Dynamic, self sustaining organizations in general have leaders who understand that there is a symbiotic relationship with the people who make up the organization. You want something from the workers, then you have to give them a piece of the pie. Henry Ford understood that if people made a decent living, they could buy his cars, and his business would be self sustaining. Socialism doesn't have that dynamic - more get along at survival level in practice. Rule by committee isn't efficient; and, in fact, there are far more natural followers (workers) than natural leaders.
Greed and avarice don't work well in any system because when there is no real reward for production then there is no incentive to produce once the basic needs (food and shelter) are met. If the state, commune, collective provide those and there is no hope of having things like a real house, cars, appliances other than junk from another collective then... No hope for a better life pretty much always equals little real work effort in any system. Corporations that ship jobs overseas for the low cost labor cannot be self-sustaining in the long run because eventually there is no one to buy their goods. If you want to consider a view such as Henry Ford's a compromise between socialism and capitalism - fine; but it is really just a matter of common sense, and there's not a lot of that going around these days.
