If someone were to ask you to think of either extreme of the political spectrum, odds are you would immediately picture a swastika at one end and a hammer and sickle at the other. Regardless of your views on the left-right paradigm or whether or not you subscribe to horseshoe theory, we (rightfully) tend to perceive fascism and communism as the standard ideologies of the extreme.
As such, many of us would also feel rather uneasy seeing those two symbols. Upon seeing a swastika, we are immediately reminded of the evils of the Nazi regime and are accordingly repulsed. To publicly display the logo is even a crime in many European countries. We understand how abhorrent the ideology is and treat it accordingly with disrespect and disgust.
But how do we react to the hammer and sickle? I don't have to write an article explaining the millions of deaths that occurred at the hands of communist regimes; like the Holocaust, the gulags of the Soviet Union and killing fields of Cambodia are widely known.