It's because Marxism is an ugly ideology, and it doesn't take long for an ugly interior to become an ugly exterior.

"What comes out of a person is what defiles him. For from within, out of the heart of man, come evil thoughts, sexual immorality, theft, murder, adultery, coveting, wickedness, deceit, sensuality, envy, slander, pride, foolishness. All these evil things come from within, and they defile a person." -Jesus, Mark 7:20-23

"God has said that the inward vessel shall be cleansed first, and then shall the outer vessel be cleansed also." -Captain Moroni, Alma 60:23

https://youtu.be/Ndpff0JkvEo