I see your point, the only thing is that Marx was not just a dreamer like other philosophers who are considered initiators of certain movements. He was an instigator, he was someone who would have applied everything he wrote, and who wouldn't have thought twice about achieving the proletarian revolution. Also, lots of stuff he wrote is very applicable and written to be applied. Just read some excerpts of his biographies.

Of course, blaming him for all the evils of the Soviet Union, communist China, etc. is largely inappropriate. But he denounced God so the burning in hell part would be right if there was a heaven, a hell, and all that was written in the Bible was correct :P