Hey, thank you! Actually, as a person who can produce extremely large amounts of coherent text really fast, I find this oddly reassuring. I have a limited number of things to say but I can certainly say them a lot.
I might be overestimating how much of his success is him, but look at the situation as you've drawn it: he's not in a fishbowl with 40 million readers, he's in a fishbowl with 40 similar fish. He's the biggest one. Well, how did that happen? 39 other fish would like to know.
I don't think you sent this to me personally, but it has been sent to me. I still like it quite a bit. I reread it now to make sure of that!
I think your summary (and additional analysis) is pretty accurate. I think I would add a few things:
There's a crunchy systemic thing I want to add. I'm sure Elizabeth Sandifer gets this, it's just not rhetorically spotlit in her post --
A lot of people who analyze Scott Alexander have difficulty assigning emotional needs to his viewers. Scott Alexander decides to align himself with Gamergate supporters in his feminism post: Gamergate isn't a thing you do when you're in a psychologically normal place.
An old Startup Guy proverb says that you should "sell painkillers, not vitamins" -- you want people to lurch for your thing when they're doing badly because you're the only thing that will actually solve their problem. When people treat Scott Alexander's viewers as if they're smug, psychologically healthy startup twits, they typically take his viewers' engagement with Scott Alexander and make it into this supererogatory thing that his audience could give up or substitute at any time. His influence by this account is vitamin-like.
This makes the tech narcissists seem oddly stronger than normal people, who are totally distorted by their need for approval. We kind of treat them like permanent twisted reflections of normal people and therefore act as if there's no need for funhouse mirrors to distort them. We make the even more fundamental error of treating them like they know who they are.
This is how I think it actually works: the narcissists you meet are not completely different from you. They're not unmoored from ethics or extremely sadistic. They're often extremely ambivalent -- there's a clash of attitudes in their heads that prevents them from taking all the contradictory feelings inside them and reifying them as an actual opinion.
From what I can tell, Scott is actually extremely effective at solving the problem of "temporarily feeling like a horrible person." He's specifically good at performing virtue and kindness when advocating for especially horrible views. He's good at making the thing you wanted to do anyway feel like the difficult last resort in a field of bad options.
I'll admit -- as a person with these traits, this is another place where the basis for my analysis seems completely obvious to me, yet I see an endless dogpile of nerds who seem as if they willfully do not engage with it. I assume they thought of it, find it convincing on some level and therefore they make significant effort to repress it. If I'm going to be conceited for a moment, though, this is probably simultaneously expecting too much intelligence and too much conventionally narcissistic behavior from my audience, who are, demographically, the same people who thought Scott was brilliant in the first place.