I'm with J Lou. Even Marx considered capital a valid input to the production process. He just thought it was being misused.
He believed the workers should control capital democratically. He believed our current treatment of capital (what capital entitles a person to do under our current system) was destroying people's lives and hope and autonomy.
But Marx and Engels actually dedicated several paragraphs of the Communist Manifesto to explaining why capital should not be destroyed during the overthrow of the bourgeoisie -- indicating that they did believe capital to be valuable.
Yeah! Was he Donald Trump -- the person -- president? Or was it "Donald Trump" the legal entity? Is his name capitalized on the documents? Was his presidency valid under maritime law?