Personal theory, and not backed by any hard data: I think at least half of the men in those online incel communities or actively identifying as incels and subscribing to the black pill are likely on the neurodivergent spectrum.
I believe neurodivergence might explain why many of these guys first embraced PUA/TRP--it provided what seemed an easy road map for guys who likely lacked any good social cue recognition, and/or were prone to black and white thinking. A great deal of PUA/TRP seems to involve mask wearing, and attempting to improve social standing--this must appeal to neurodivergent guys who feel hopeless in the social interaction department, guys whose past attempts at actually being themselves (hey, they were likely told that's all they needed to do to find friends and lovers) backfired miserably and left them feeling more rejected by society and the opposite sex.
When PUA/TRP failed them, Black Pill was likely the next logical step, at least in their minds. Unfortunately, black pill theory, while based in correct science, provides a terrible road map for these men. (Self-improvement and overcoming the desire for external female validation is the only real way.)
This suspicion that most of these guys are either neurodivergent or mentally ill is why I find it icky when I see people laughing about incels or wishing death upon them all. Most of them need serious therapy or mental health treatment. Similarly, I don't really enjoy laughing at a lot of radfems and TERPs, because when you encounter them, a lot of the time something is off and it's apparent there is either mental illness or neurodivergence occurring. This forum used to have 1 or 2 pretty hardcore radfem types and I suspect there was something going on under all of the sloganeering and anger, some real frustrations stemming from poor impressions of and/or experience with the opposite sex. Same case with some past "red piller" members.
TL;DR I think neurodivergent Men and Women are especially vulnerable to the messages of extreme gender politics; I think most incel/PUA men are probably autistic or neurodivergent.
Neurotypical = Sensor 2/3 of population,
neurodiverse = Intuitive 1/3 of population
Mainstream mating culture = geared towards sensors. Neurodiverse try to fit in the mating rituals and fail. Nobody tells them that they don't have to conform.
They try to find out a manual for it, they end up finding game tactics geared towards sensors, such as PUA, which they are ill-equipped to apply by nature.
Eccentric personality disorders are more common in neurodiverse population whereas abusive/exploitative disorders (such as NPD, HPD, BPD, Antisocial PD etc) are more common in the neurotypical population.
Neurodiverse people are easier targets for people with NPD, BPD, HPD, Antisocial PD because they are not keen to the social mindgames being played. So that might have a role.
What I noticed for myself is that I was failing to make a girlfriend because I've been barking at the wrong trees (i.e. neurotypicals). Once I noticed that, I've become more at peace with myself and I don't feel the need to actively seek a relationship, though I'd welcome one with a compatible neurodiverse partner.
I noticed that the higher the Se and Ti functions, the more physicalllu abusive/exploitative a person becomes.
I don't know much about incels, but from what I read on wiki, they sound like INTPs whereas MGTOWs sound like xSTPs.