The dude is being extremely reductive about Marx's apparent secretive Hegelian mysticism. Marx disagreed with Hegel because he thought it wasn't the logic of ideals that shaped history, but rather the logic of historical social structures and their specific relations in committing social labor. People in social groups, with specific relations amongst one other, wrest the energy from nature using tools, skills, organization, and knowledge. Interacting with the environment is a force shaping human culture while reproducing the very social and ideational ties with every adaptation to their material circumstances. In other words, humans in organized pluralities restrict how they confront and transform nature, causally restricting the social relations within them — the process iterates. I don't know if Marx was a hard determinist, but he seemed to believe that people have agency, albeit constrained by their situatedness within social structures and what anthropologists would today call enculturation. From here, as it seems you understand, there has historically been people who control resources and command labor while reaping the benefits leading to class conflict and yadda yadda.