Could it be that some of these “incels” are the ones you hear about that convert to Islam and soon thereafter commit a terrorist act (with the promise of paradise)? I hadn’t heard if the term “incel” either. But maybe some (not all) are radicalized into Islam. That would explain a lot. No normal 20 year old Western male is likely to be enticed with the prospects of martyrdom and the promise of paradise, but it might be just the sort of thing an “incel” might find attractive to channel his energy and hatred.
This is the natural man standard prevalent in many backward cultures and the reason Islam and pre-Columbian Native Americans allowed men to have up to four wives.
They dealt with the surplus of men by wars, slavery and turning them into eunuchs or sacrifices. That's the harsh reality.
Christianity, with its roots in another civilized religion (Judaism), brought in two new concepts called monogamy and spiritually training people in overcoming the natural man. It also normalized it by making male and female equal in the sight of God but with different and distinct roles in the family. This is why the Left is so anxious to undermine the family concept and turn the clock back by making the concept of monogamy and family fit that of the natural man.
One symptom is the Left's energetic push to appoint judges who are hostile to the traditional Judeo-Christian family unit. Four members of our Supreme Court fit that mold perfectly whereas two (Kennedy and Roberts) will drift into that territory often.