Marx is one thing, but I see no difference between the worship of Stalin/Lenin and the worship of Hitler. In both cases one is worshipping a murderous tyrant.
I mention Marx in my class. He was a brilliant economist and his analysis was amazing. There was just one problem - he was wrong. He couldn't account for innovation. This isn't surprising - many western economists couldn't as well. For example, Malthus had a brilliant insight that led to the conclusion that famine would be the order of the day. His pitfall was he couldn't envision one man on a tractor feeding an entire city.If Marx was right and the rate of profit fell which is a direct result of the law of diminishing returns ( add capital to a finite resource and its return will fall) then there would have been a revolution. The subsistence level of wages has a floor. Unfortunately the end result of the workers owning the means of production and sharing equally in the output would have never worked. That has been demonstrated many times. Outside of Castro and those nuts in your video not many people believe this anymore.
Marx was brilliant but he didn't account for Russian people who took his ideas and turned them into a horrific nightmare aka revolution.