But you don't find many, if any, societies in the Communism + freedom quadrant.
The other three quadrants have many examples. And those tyrannies that have become more free over time have usually needed a dose of capitalism as the first step (ending collective enterprises, especially farms, and trading with capitalist markets, for example).
Even if there was cyncism among those who grabbed power, they then elevated Communism's texts and ideals in all official communication, celebration, and education. So generations were given every chance to try "Communism in good faith".
But it still didn't work. It turned out more corrupt, more polluting, more poor, and even in many respects less egalitarian than capitalism.
To claim all those proud earnest efforts weren't "in good faith" is at best a form of the "no true scotsman" fallacy.
They weren't stupid. They knew the party line was an obvious load of crap, a fig leaf over a ruthless power grab. They went through the motions only out of fear of the secret police (in itself an acknowledgment the rulers didn't expect any loyalty). In particular, Russian cynicism about propaganda became legendary.
You don't judge actual democracy by looking at totalitarian hellholes and their blatant lies about how "democratic" they are, do you?
Was every Communist movement that took power -- Lenin, Mao, Castro, Ho Chi Minh -- dominated by ruthless power-grabbers with no allegiance to Communist ideas except as a cynical route to power from the beginning?
(If in fact these ideas are so useful to ruthless power-grabbers, and so hard to implement 'in good faith', might that alone not discredit them? Attractive, in theory; but when you try to build a popular movement around them, nastier people than ever wind up on top.)
Why, when cracks in the secret police's power finally emerge, do the people embrace property, markets, and profits rather than a chance to finally implement 'Communism in good faith'?