If Kołakowski is to be believed, Marx's view of the post-revolutionary world has a somewhat mystical flavour stemming mostly from Hegel. It is the immediate roots in Hegelian philosophy that makes it, in practical terms, wishy-washy.

What has always tied Marxism in knots has been the tension between waiting for the inexorable laws of history on the one hand (and sometimes trying to give them a hurry up) versus on the other hand agitating for reforms. The former see the latter as delaying the revolution. The latter see the former as something between dreamers and jerks.

I think that history, having been somewhat lawless after all, makes the reformers look better.