From someone who has gone to more than a few political protests and rallies in Boston:

Every fucking time Socialist Alternative shows up, it’s fine until some edgelord dipshit unfurls the fucking huge Soviet flag with Stalin and Mao silk screened on it. It’s like they’re trying to alienate reasonable people as well as historically-informed people. I consider myself a staunch socialist. I also outright detest Stalin and Mao because they were fucking authoritarian despots who wrapped their regimes in “communism” banners.

Sure, some of the systems at lower levels were socialistic, but at the end of the day, it was all in service to the cult of personality in charge of the whole gig. And yes, that’s what the US has devolved into (and arguably had done so quite a while ago, just not so overtly), but that doesn’t excuse Stalin or Mao, nor does it justify being an apologist for them.