In all the other 'revolutions' you mention, a party-clique took power, establishing not the basis for communism but another state-capitalist dictatorship, like the military dictatorships I mention above, but with a dfferent coloured flag. So, no 'attempted communism' there. To claim that 'communism failed' because the Chinese Communist Party failed, is as facile as if I claimed 'democracy failed' because the American Democratic Party failed. Only for a short time in Russia (and very briefly in parts of Germany, Hungary, Italy, Spain and a few towns and cities elsewhere) were the working class ever in control. In each case the revolution was drowned in blood by capitalism. That doesn't demonstrate communism doesn't work, it demonstrates capitalism is psychotic and sociopathic, and the capitalist class is desperate to hold on to power.