You cannot speak freely about Nazism, Francoism and Fascism because they were regimes that were against communism.

On the other hand, you can speak freely about communism and wear t-shirts with its symbol or the face of Che Guevara or Fidel Castro without any problem, despite the fact that they are the ideas that have killed the most people in history.

This gives you an idea of who won the cultural battle and who dominates the world.