The version you're used to is US government propaganda from the WW1 era originally as a way to ramp up the populace into accepting war against Stalin, tbqh. Later, this demonization was used as a way to suppress anyone claiming to support socialism, or even research into it. "You're evil. You support Stalin," they'd say. It’s been extremely successful at discrediting true socialism/communism over the past century as a result. And unfortunately, the various regimes claiming to be communist/socialist — including Stalin’s USSR, modern-day China & Venezuela, etc. — haven’t helped.
The reason I say "claiming to be communist" is because one of the core tenants of communism (and you've probably heard it often) involves workers seizing the means of production. In other words, that means workers get to control what's produced & how it's used. This core belief is proof that communism/socialism is inherently democratic. Dictatorships directly contradict that tenant since workers have no power over production or any other part of their society under such rule. Therefore, such regimes cannot be communism.