If you want to claim that intention and ability are meaningless, please come right out and say so. If you please, also describe what is left to a '"dark lord" if evil intent and the ability to achieve it are -- Waitaminute.

We're skirting an argument of definition here, so I'll just skip the quibbling and jump straight to attacks on your character, if you don't mind:

As a matter of fact I do mind, and I'm more than a little insulted. You could just ask what I mean by a Dark Lord if I don't expect it to entail deliberate evil or competence.

If someone is a totalitarian ruler who knowingly and willingly causes the deaths of a large proportion of their citizens and imposes policies that contribute to low levels of civil liberties and standards of living, I think it's fair to describe them as the real life equivalent of "dark lords," although I wouldn't describe them as such in ordinary conversation, and if you look at the context of the conversation there's nothing to imply that I would.

I think this category carves out a significant body of individuals with related characteristics. I also think that, given what we know about human nature, it's unlikely that they see themselves as people doing bad things.

Stalin and Mao incompetent? Do you beleive that clawing one's way to the top of an organization of that size and overseeing it's operation and -- yes, after a fashion -- prosperity is something that any chump within one standard deviation of the mean could stumble into like a Lotto winner?

Cold, quiet heavens, no. It takes a special breed with special lessons just to pull that off in a safe, civil environment. Doing so in place where promotions are obtained with obituaries filters for even more specialized aptitudes. Average people, Lotto winners, incompetents don't even last long on their own.

I was referring to competence at running countries, not competence at climbing social ladders. Clearly they possessed a considerable measure of the latter, but then, all of them instituted policies which could have been predicted as disastrous by people with even an ordinary measure of good sense.

It might be narratively appealing to imagine that our greatest real life villains are like Professor Quirrell, amoral and brilliant, but their actual track records suggest that while they may be good at social maneuvering, they aren't possessed of particularly good judgment or skills of self analysis.

If you want to argue my points, and get into the actual policies and psychology of these people, feel free to. But if you're going to skip straight to accusations of poor conduct and character without even bothering to ask me to clarify my point, I'm going to accuse you of being excessively hostile and having poor priors for good faith in this community.