Imo, a problem with Marx, is that tha the languaje he used lend itself to very broad interpretations, thus making it easy to absorb him into whatever ideology/plan/scheme.
People who like Stalin or Mao and in a lesser degree Trotsky and Lennin -which to whom we nowadays call commnunists- used his languaje to reaffirm their ideas. Even tho imo their ideoligical brand was quite a ways out of Marx.