There are lots of good reasons for the failures so far. In the absence of thoughtful opposition, it is very easy to fall in love with illusions of personal infallibility, invincibility, or even immortality. One's own perception of reality can seem to be all there is. Lack of mental exercise creates a flabbiness that allows such absurdities to seem believable. Flabbiness easily leads to corruption, or just to well-meaning megalomania.
Unchecked authority breeds passive-aggression in devoted followers with alarming consistency.
These things are just what happens without the safeguard of strong people and good group dialogue. I believe that it is simply not possible to surrender autonomy without creating too much dependence, too much destructive, competitive drive for the leader's approval, together with corresponding terror of disapproval or criticism. In any event, all this craziness easily frustrates the best-intentioned attempts to exchange the current information on which good problem solving rests. Kat Kinkade co-founded Twin Oaks and East Wind communities, and helped start Acorn community. Mildred Gordon has an extensive background in group facilitation and training of group leaders.