It is unobvious to me. K&C called it bravery for a black person to say he's proud to be of his race and won't let others define him as a lesser being. He called it pathetic for white people to do the same. His explanation for why it's pathetic was that some whites did bad things. But of course some blacks did bad things too. So why the difference? What context clarifies this that I have failed to take into account? How have I misinterpreted his comments? What possible other interpretation of what he said is there besides that he is laying the wrongdoings of some whites at the door of different whites? If it's obvious to anyone, or at least if it's obvious to you, then help me out here.
In the first place, all white women are specific white women. What, should a specific black woman not perceive herself as attacked when somebody makes a racist sexist remark about black women in general?
And in the second place, Ms. Jackson et al. aren't only charging a whole demographic with complicity; they're also inviting themselves to have a white woman serve them dinner while they accuse her of complicity in person. Is that specific enough for you?
First, taking your argument as valid it is not blaming current white people for the past wrongdoings of white people.
I didn't say blaming; I said holding responsible. That's a broader concept: "liable to be called on to answer", "accountable".
Second, the propagandists are not arguing that any single person could make anything go away. They are arguing that by doing nothing, they are complicit.
No, they're not arguing that. They explicitly say even if the targets of their invective are doing something -- denouncing Trump, the KKK and Nazis -- they're still complicit. And they explicitly say "ALL WHITE PEOPLE" must acknowledge their complicity, without making any exception for the ones who are doing a heck of a lot more. It is not just the women doing nothing whom they are saying "as a white person in America, you are an active participant in upholding white supremacy" to.
They are not arguing that anyone has to be successful in their actions to undo white supremacy.
Indeed; they are arguing that no matter what actions any woman takes to undo white supremacy, she will still be upholding it. It's a very Christian-like attitude: there can be no salvation through works. You're a sinner regardless of anything in particular that you have or haven't done. You have to confess your sinful nature and hope for forgiveness.
As Walsh said, "the point is to defy the Left's rules just for the sake of defying them". If you don't perceive the people attempting to impose such rules as "the Left", well, your perception isn't the pertinent one.
True, but if these people are not really leftists, then it makes seem Walsh like more like a reactionary moron than a perceptive commentator about society.
That argument presupposes that the political spectrum has an objective origin and "left" and "right" aren't purely relational concepts.
But if you think whether they are objectively leftists makes a difference for whatever reason, feel free to propose an objective criterion for "leftist" and then we can examine whether the people I named qualify.
My point is that the term “leftist” is thrown around as a pejorative rather than as a descriptor. You claimed certain people were leftists, and you have yet to substantiate your claim of fact even after asked to do so. Which suggests your use was rhetorical rather than descriptive.
No worries. Since you decline to offer a criterion for "leftist", it falls to me. I'm a centrist. Therefore anyone who takes positions further left than my own is a leftist.

All the people I named have taken such positions; that's why I perceived them to be leftists; that's what my descriptive statement about them communicated.
If that's not enough to satisfy you, AthenaAwakened calls herself an anarchosyndicalist and said "First, we kill all the bankers." Will you dispute that calling her a leftist is descriptive?