Do capitalists in the Marxism world view create value?
I'm not a Marx expert, but I've read The Capital some years ago and as far as I can remember Marx said that only the workers produce value. All others' wages (and the workers' wages too!) and other costs are covered by the produced values of the workers, so the others decrease the "profit", which could remain at the workers otherwise. Therefore Marx suggested the workers to make collectives without any capitalists.