I agree with others above that Warren is evil as conventionally understood. The reasons offered above are valid enough in this context, and there isn't anything to add that comes to mind.
That being said I will also say that in principle I rarely use the word evil, and never in categorical terms. Used categorically, I think it does harm because in the process of completely excluding someone in that way from everyone else, it encourages us to comfortably turn away from our own capacities for "evil" too. Hitler for example is what is considered an obvious example of evil, and I understand what people mean, but let us not overlook that many people had or have the capacity to fall for that form of moral behavior as well. I think it's better not to deny the humanity even in so-called evil people, because it can still serve as a useful reminder to the rest of us that, in certain relevant ways, we share more in common then we don't with these people and that we need to be vigilant not to allow ourselves to follow our own similar dark paths. As much as we'd like to deny it about ourselves, capacities of one sort or another of an "evil" nature exist within each of us. The human condition is a struggle with both light and dark forces, and it's a struggle that every one of us has to deal with. So why do we need to define some people as categorically different than the rest of us? In some ways the question reminds me of the problem of categorizing people as "the Other" in colonial studies or critical race theory. When they are "Other" they no longer have anything in common with us, and if they don't have anything in common with us we can safely justify anything and do with them afterwards whatever we wish.
The problem for me is that we don't really have adequate language to make finer distinctions about "evil", "bad" etc. to do justice to finer gradations and so forth. Nietzsche diagnosed this exact problem with his genealogy of ethical concepts in history. The oppressed classes in history have tended to classify ethical terms like "evil" in categorical ways as a means to express and feel their own agency and power and which were motivated largely by self-preservation. By contrast, those in power have the tendency to brush finer distinctions aside as well, to maintain a status quo. We are the inheritors of this genealogical history of moral concepts. Add to this the idea that, as modern people, the price we continue to pay for our moral inheritance is the guilty conscience, which in this context presents further difficulties, because we can't even make a good faith attempt at objectivity anymore without feeling this sting of conscience and as a result this continues to encourage a categorical and black/white attitude about it. That's why Nietzsche once remarked that the sting of conscience is in a way stupid, because it signifies a weak will or lack of willingness to think further. I've simplified Nietzsche's argument quite a bit here but the general idea is part of the problem for why I find moral discussions like this one a little frustrating. Also consider the contemporary phenomenon of sexuality: increasingly gender and sex are considered less as a binary, and as a result a new space has opened up where many different shades of sexual and gender identity have emerged to take the place of the old binaries. Morality needs a similar revolution like this I think.
I think many people realize this at least on a basic level (this is even brought up in a Harry Potter novel and movie)...that we are our choices rather than our temptations. I'm therefore fine with using "evil" when someone is being evil.
But some people do project their own shadow selves or use it to be evil themselves. Just because some misuse the word doesn't mean all do. Of course our biases (be it for family or lover, church or state) can muddle our senses, but that doesn't mean some aren't evil, as in choosing to act in a certain way. And I dislike claims of "fungible" evil (implying everyone of a certain race, religion, nationality, political party, gender, profession, etc, are evil)--though also claims that some cannot be considered evil because they are of a certain race, religion, gender, political party, profession, etc.
It's also a classic, probably ancient, saying that the laws are the protection of the mighty and the burden of the poor. Governments and other centers of authority have gone to great lengths to tell us violence never works (even as they throw much or even most of their budget to police, military, and/or security) when they do. The violent parts get whitewashed out because they don't want a repeat of that, and call it evil, when without the violence we'd still live in a much more oppressive society today.
In addition to revisionists, they make heavy use of spin doctors and even psychological techniques to muddy our language so that words can't be trusted, and in many cases I'd be careful about the word as well--just as I am when someone is called a racist, misogynist, incel, SJW, fascist, Stalinist, etc, because the words are abused too much by people who don't really know what it means or because they're deliberately trying to poison the well of discourse (offhand my "favorite" was when Food Not Bombs got labeled "food terrorists" by a mayor, IIRC, for feeding the homeless in some Florida town, and wanting anti-terrorism laws to apply to them).
And unfortunately, scum has a way of rising to the top. And no, I don't believe we'd all be corrupt if given that power, but those who are are going to be are drawn to it the most, and find it the easiest to make the dirty deals they need to. (And I'm not sure what to think of one US President in particular from before I was born...the guy was crazy, I wouldn't have allowed him anywhere near me or anyone I knew even when he was sober, certainly would NOT have had a beer with him, but he did a lot of things I think were good, even if I'm fairly certain he was being pragmatic about it. Actually, I prefer enlightened pragmaticists to idealists.)
There are some people I'd NEVER let babysit a kid. It has nothing to do with their demographic and everything with their behavior, particularly when it's a pattern.
And I will continue to identify that pattern, however problematic it may be (and how wrong I may be at times). The alternative is worse, or so it seems to me.
I was once friends with a philosophical nihilist, however. He thought the very idea of morality is what made for such problems that led to oppression, inquisitions, suppression of free thought and innovation, and the like. He definitely believed rebellion was our most noble attribute, and that if Eve were real then she was a heroine with humanity in her debt. Unfortunately, I'd lost contact with him before I saw Buffy season 6. I might've thought to had him watch just to get some commentary on it, assuming he would even bother (he was also one of those "kill your TV" people).
I doubt he'd have much good to say about Warren, however. He rejected morality because he felt that it led to evil oppression, not that he felt morality restrained us from being all that we could be. He did understand that society was better to have "I don't kill you, you don't kill me" (etc) in place. He was more of an artist than an academic.
And in this case, your concerns, while valid, don't really apply here. Warren isn't called evil because of his demographic or flouting traditional thought (if anything, he embraced a lot of traditional values rather than challenged them, even if he chose to "rule in Hell than serve in Heaven"), but because of what he did and why he did it.
But yeah, it runs into the same problem of identifying fake news, only for those who spread fake news to yell the loudest that everyone else, including fact checking sites that debunk them, are the fake news. Frustrating, that, and I'm at a loss at what can be done about it.
