How a party evolves depends on who are in the party and what kinds of thoughts they hold. Any party occupied by a group of “Angry Young Man” (Fenqing, 憤青) becomes a one-party fascist dictatorship in the end.
Actually, there is no one who cares whether he is joining the Communist Party or not. No one cares about the name or ideology. Everyone just cares in what way his actions can be seen as “Great”, “Glorious” and “Right”, or in what way he can acquire power of a town without the consent of the local citizens, or in what way he can extinguish other voices with his power. The party members make the party, what they care make the party. The original ideology of the party is comparatively less important. With absolute power, ideology can be distorted.
Let’s say in someday you destroyed the Communist Party, and set up, say, a “Federal Republic of China”, ok? However, if the Republic still consisted of the same people, and that the power structure remained centralized, and that some thoughts are still regarded as heinous, that Republic would end up the same. It is not the name that matters.
Even the Communist Party was ousted, its people, attitude, culture and daily ways of life remain. All these things will reincarnate as another power or party, though in a different name, but not much difference in behaviour. So the problem remains unsolved.
This problem cannot be explained just by cultural determinism. The point is not who you oust. The point is, evil grows like mold – it grows under favourable environment. Cleaning up the room does not prevent it from growing again, provided the the favourable environment remains.
The Communist Party is therefore a consequence, not a reason. It evolves to become what it looks like today, which is different from what is looks in day one. In the blueprint to an ideal society, the party can be ousted. But the statement which says “just to kick the Communist Party away and then we can get an ideal society” is false.
The Communist Party is not the only dictatorial or cruel totalitarianism in history. There were many before it, and for sure there will be many in future. Take Russia as an example. The Tsar before the communists did not seem much better either.