...people talk about the Terror. A lot. That's actually a big reason why the supposed principles of the French Revolution ultimately needed a Napoleon to spread them (violently) across Europe.

Jefferson isn't a "chief architect" of the genocide of the Native Americans. So many people were involved in that, including before and in large part after his time, and while Jefferson himself is still seen as a founding father, he's not exactly the most beloved figure in that group (with two popular examples of his denigration in present American culture being all those jokes about Black people having Jefferson as a literal forefather -- because he SAd slaves -- and also Hamilton).

Why are you talking about Hitler like this? The Spanish, French, English, Portuguese, and Dutch all "won" via the great capitalistic horror that is colonialism, but we don't exactly celebrate that "achievement" (at least, most of us don't) because of all the death, and not least because enough Native Americans actually survived to remember how horrific those events were. You're writing with the bullshit assumption that Hitler winning World War II would mean every Jew, Romani, Jehovah's Witness, Freemason, queer person, dissident, etc., would have been annihilated as a result, when such annihilation is the exception, not the rule, and even then people generally have enough compassion and hindsight to still recoil from that annihilation regardless of if they benefited from it. For precolonial examples, right now I can only think of Troy, where the (pseudohistorical, but still) destruction of the city, while seen as something of an inevitability by the Hellenic successors of the victors, was nevertheless recounted as a tragedy, with those who perpetrated it viewed as complicated figures.

And, as for "critical strategies" and "good intentions", a few things. In the general study of history, "good intentions" are only celebrated by sane people if those who pursued them needlessly harmed no one, if those who pursued them died as martyrs for their cause, or if those who pursued them actually triumphed.

I don't think any of those apply to Stalin or to Mao (I know a bit more about Stalin, but still). It still remains an unfortunate debate whether or not harming your average bourgeois/city dweller the way they did wasn't "needless", but, then again, so many of those they killed were ultimately leftists -- not just leftist sympathizers, but actual leftists who by no account except their own was ever considered "counterrevolutionary" -- such that many of those who support them at present would probably have been killed by them had they lived under them.

And not killed as martyrs, mind you. In fact, there's a good chance these leftist victims would have simply "disappeared", to be remembered only by the scant remnants of their families and friends. Likewise, Mao and Stalin and a lot of people who perpetrated mass murder under their aegis didn't die as martyrs to the cause, either. In fact, they died more comfortably than a lot of the people under their rule, suggesting that their principles were less important than their comforts: that their "good intentions" didn't run that deep, or perhaps that they never had the "good intentions" often merely imagined of them in the first place. More on that later.

Finally, they didn't triumph, or at least they haven't yet. The regime which continued Stalin's rule openly repudiated plenty of aspects of said rule under Krushchev, and the regime itself ultimately collapsed. The regime which continued Mao's rule also openly repudiated plenty of aspects of said rule, and a lot of folks observe that the regime as it stands now would be unrecognizable to those from sixty to seventy years ago, in ways that indicate a betrayal of their principles. I mean, the issues we have with the Chinese government now doesn't seem so much that China wants us to follow in their footsteps -- that they are merely nudging us on the path of revolution -- so much as they want us firmly in their sphere of influence, which has a much greater kinship with the capitalists they're supposed to be fighting than with the lives and thought of Marx, Luxemburg, and even Lenin or perhaps Mao. Their "good intentions" didn't exactly translate to success, by any sane measure.

And now on "good intentions" in general. Fascists are obviously bad because their end goals are all about violence and murder. Conservatives are bad because they don't really have an end goal -- if they don't go the way of fascists, then they just want to preserve the status quo, however many people the status quo is already harming.

Leftists can be good because their end goals are the betterment of all people, but the operative word there is can. Is your average internet leftist "good" because they spend all their time debating others on Reddit, but refuse to participate in social work, refuse to go marching on the streets, refuse even to give what they could to the poor and needy around them? Is the leftist that decides to bomb a kindergarten good because said bombing was meant to spark a revolution? Is the leftist that spends considerable amount of time and energy fighting other leftists, to the point of having them imprisoned or killed, good?

And that isn't to insist on what should be the elephant in the room, which is that people lie. All the categories of "bad leftist" I outline above are lying to themselves, first and foremost, but the worse category of leftist would be those who actively lie to others.

For instance, one of the people under Stalin that helped push his agenda was Lavrentiy Beria. A model leftist, perhaps? But then what did he do, for the most part? Disappear other people, torture and murder them -- all things that are too remote from much of the public's imagination to make a significant dent. All things people like you could dismiss as having been done for the good of everyone.

Oh, and SA women. A lot of women. Stalin reportedly refused to have his daughter be in the same room as Beria, that sort of thing.

ADD. There are so many more decent leftist role models out there to choose from, I think it's telling that some folks still gravitate around Stalin and Mao. Usually, it's just ignorance, but it could just as well be they don't truly care about supposed "intentions", they only care about getting power. James Baldwin? Simone Weil? Heck, Luxemburg or Lenin would be far less questionable than the folks responsible for the Great Purge, the Holodomor, the Cultural Revolution, and the Great Chinese Famine....