I'd argue the repression of reactionaries was part of the secret sauce that made it work so well. We saw what happened when they were loosened in the 90s.
I'd posit that the rise of the Nazis (which caused the rise of the SFR Yugoslavia as a resistance movement) taught us differently.
Karl Popper, himself an Austrian that saw the rise of the Nazis and had to live in exile as a result famously formulated it as the paradox of tolerance.
