[ikurei]

Because their argument, in which they do have faith, is that a cacophony of disagreeing viewpoints casting doubts on the common national project is hurtful, even if those doubts are unfounded and those viewpoints unsubstantiated.

I'm not defending autoritarianism or communism, but I think you're just not putting yourself in their shoes and looking at things from their POV. They supress other viewpoints not because they're afraid to be shown wrong, but because they believe it's best to supress them and not have people confused by enemy missinformation.

(Not an expert, but this is my impression from talking to both chinese and vietnamese people who defend or at least don't oppose their communist governments, and also spanish autoritarians who defend the Francoist regime. I used to think they were brainwashed/dumb/evil, and now I think their worldview makes a bit of sense, even if it's still misguided.)

[kelipso]

One of the reasons for the collapse of the USSR was that the propaganda done by the US was better than the propaganda done by the Soviets. So it's not like there isn't a historical reason for this either.

[ptero]

A much bigger reason for the collapse was that the planned economy and distribution (plus military spending) failed to produce enough basic goods and quality of life for many started dropping.

To the extent that party elite started building their own, parallel universe of food, summer camps for kids, apartments, shops, etc. closed to the ordinary people. It was clear to many people that the Soviet road, as followed, goes to a variant of a North Korea lifestyle.