Well said.
I believe a fraction of them are actual authoritarian sympathizers, and are just hoping "their brand" will align with a future hypothetical autocrat.
They don't want actual justice, they just want to reroll the dice and hopefully come out on top.
To the other fraction, I think those folks are exactly the folks who completed those movements you mentioned. They worked hard to push the existing system towards their goal, often starting from a very weak position.
That pushing largely isn't done, and it is less glamorous and obvious compared to flipping the table, killing the current leaders (and a bunch of other demonized but innocent groups oopsie daisy) and trying again. That's how you get a Khmer rouge and then a pol pot.
We need another MLK and his contemporaries.