I don't think it's clear on longtermist grounds. Some possibilities:
(I'm not sure what my bottom line view is.)
In general, I worry that we're basically clueless about the long-run consequences of most neartermist interventions.
People who have a very strong "will-to-Goodness" don't necessarily have very strong/extreme shadows, but often do, because they created the very strong will-to-Goodness by strongly suppressing their antisocial desires, which then strongly polarized those desires.
How much data do you have about people with a very strong "will-to-Goodness" having strong shadows? It doesn't match my anecdata, and I find it more plausible on priors that most people with strong "will-to-Goodness" tend to not have had e.g. childhoods that taught them the world was zero-sum, and/or have less of the genes that cause people to be dark triad.
I mean that their BDSM-like desires are cooperating strongly enough with their other desires that they're a little bit present most of the time, rather than driving them to create simulacra of highly transgressive behavior.
This was interesting to read because I often like to make slightly mean-spirited jokes. (I didn't know about shadow work before reading your comment, but having read about it now it sounds like it's something I've pretty much always been doing casually and regularly.)
I think it's useful to distinguish between dominance in the "taking control" sense and the sadistic sense. They seem correlated but are separable in principle. (I have the former, just not the latter.)
I'd guess that Richard was also mostly replying to the aspects of dominance that are conceptually closer to sadism.
(I'm a regular poster/commenter on LW; I don't feel comfortable saying this under my real name for various reasons.)
I'm horrified by the fact that some men have sexual kinks like the ones that John describes having. My (m/ hetero/experienced) own sexuality is well-described as a reflection of my identity and values: I'm moderately but not extremely dominant,[1] mostly playful and passionate, and want everyone to have a great time.
My attitude towards John has moved from skepticism to distrust. I wonder if I'll learn that people can be deeply good while having violent sexual preferences at the same time. Anecdotally, so far I found that men with violent sexual kinks also tend to be slightly creepy in other ways. I did find John a bit creepy when I met him in person some time ago.
ETA: By dominant here I only mean "liking to take control", and want to differentiate it from sadism.
Is it actually true that Eliezer likes hurting people in bed? I think I recall reading something from him where he claims that orgasm denial is a central example of what he's into, which sounds spiritually different to me.