"Marxism doesn't only not work, it can't work."
There you have it in a nutshell. Trying to make Marxism actually work is like trying to make a paper airplane that can fly non-stop across the Pacific Ocean. It flies OK in the office, but out in the Real World, it is just a piece of paper. Marxism works fine in the offices of academics and radicals, but in the Real World, it is just a piece of paper.