it is bad becase it erradicated , completely destroys the rich ruling capitalist class. and they do not want that to happen to them. it their existential threat.  and it has failed because the workers turned out to be no class, just mindless sheep who prefer to try to become capitalists and have their own slaves to worknfor them, to become the bourgeoisie (small time businesses) than to remain workers and live in equality with other workers.
Pirate