There's more to the extreme left than "Everyone deserves to be treated equally and with dignity."
Politics in the US lacks nuance. You can be politically moderate and lean towards the left. It isn't simply conservative wolves in centrist clothing.
I can vehemently disagree about many things that extreme leftists do and still vote for one over Donald Trump. But that doesn't mean voting for Donald Trump automatically makes someone a Nazi either.
The problem is that even suggesting that equality and dignity are valid as bedrock communal values in business, politics, law, and economics is considered an aggressively extremist ultra-left position in the US - and not a sane and mature common sense centre-left view, as it is in parts of Europe.
There's a reason for this, and it's to do with the real bedrock values of US culture.
Bottom line is the Left in the US operates the same way as the rest of US culture does.
And the underlying problem is understanding why, not complaining about superficial dynamics that are actually consistent with the way the culture operates as a whole.
What you're not getting is that equality and dignity aren't even compatible if you try to push equality to extremes. Dignity means giving people freedom to make their own choices and live as they wish; the opposite of dignity is enslaving them. But as soon as people can make different choices they'll start achieving different outcomes - inequality. Not to mention the need to forcefully people who step out of their assigned 'equal' band of achievement - there's nothing dignified about crabs in a bucket.
NK and Cuba and USSR stamped out inequality pretty well, and they gave up on dignity to accomplish that.
You sound like a rational person. If I give you three examples of current capitalist ideology authoritarian states (one more example than you gave), reason would dictate that you will of course instantly become a leftest because you are a rational person and by your own self-described logic, the correct ideology is determined by which ideological system has a higher count of authoritarian states.
Far-left: 100% Far-right: 100%
There are leftists in the US to whom equality and dignity are the foundations of their belief system. However, that doesn't represent the whole of leftism in the US and it certainly doesn't represent the foundation of actual leftist extremism in America.
To clarify, I don't think most people that fall on the left half of the political spectrum in the United States are extremists. I think that due to their fanaticism and tendency to be more vocal, the extremists have a voice disproportionate to their actual size.
That doesn't mean they don't matter. It just means they don't represent as many people on the left as one would perceive them to based on social media and mainstream media.
I'm not a leftist extremist. I'm a socially liberal moderate that likes the general idea of free market competition but understands that completely unregulated markets are probably just as toxic and doomed to fail as attempts to form completely planned economies. Prudent regulation can minimize predatory and exploitative behavior.
I think there is a balance to be struck between people having individual freedoms and the ability of the government to take measures to prevent groups of people from making it impossible for marginalized groups of people to live enjoyable lives in the US.
My search for that balance is founded on a desire for equality and dignity. For example, I don't think a city or state full of racists/homophobes should be able to use States' rights protections to establish bubbles where its impossible for certain minorities to comfortably exist.
However, I believe that we are often really quick to take knee jerk reactions and pass legislation that may have unintended consequences when it comes to preserving everyone's freedom, equality, and dignity.
You may choose to ignore them, but there are vocal voices in the progressive movement that are racist and sexist and are more interested in establishing a society that revolves around revenge against white people. Some of them are nobodies, but some of them are influential people in places of power in various industries.
Leftist extremism exists. There are people advocating for violence against white people and men in general on Twitter for a daily basis. Reporting these people usually gets ignored.
I'm opposed to leftist extremism and conservative extremism. People that advocate for violence and who advocate for a new type of inequality are assholes, regardless of how many of their unrelated political opinions I might share with them.
I do, however, believe that the US has more work to do in regards to how it treats many different minority groups. I also believe that white privilege exists. I don't think every white person faces a life-changing situation where they benefit from it, but it happens. In my case I'm not sure how much of an impact it had, but it probably had an impact.
You can't vote for a party and try to avoid taking the whole package deal. You get what you voted for.
Again: You get what you vote for. Using 'I disagree with what my party is doing, but I'm voting for them anyways' as an attempt to avoid criticism doesn't work. That's the nature of US politics. If you vote for one party despite them doing some heinous things, then you tacitly support what they're doing. If you don't like it, then either don't vote or vote for the opposite party.
But part of that compromise is that you accept the party is going to also do things you don't like. Which is something you can't escape criticism for. Voting is approval for that party. You're choosing to value what Party B does over Party A, which means you weigh the negatives of Party B as being less of a problem than the positives.
That doesn't mean you get to avoid those negatives when someone else calls you out on who you decided to throw your lot in with.
I'm not asking a rhetorical question, genuinely interested in how you see this. It doesn't seem like to me like he falls in any of the categories you listed. Same with Lee Fang, the interviewer who got attacked for publishing Max's remarks.