Alright. Time for an effortpost.
Incels™ (with a capital I and a trademark symbol) are a cult. I mean that in a 100% literal sense. They have their own saints, their own jargon, their own purity tests, they disown/punish apostates (just look at how they react to incels who eventually escape/have sex), and most importantly, they prey on lonely people. I feel like most people don't understand this about cults. Cults don't target stupid people, or evil people, they target LONELY PEOPLE. And incels (lowercase I) are lonely people almost by definition. Some have male friends and hobbies and jobs, but many of the same factors that contribute to their inceldom make this less likely than average.
So imagine a man, let's say around 25. He feels like he's doing pretty well in life, for the most part. He's a working professional, no supermodel but not bad looking, doesn't go out and party but has a few close friends. But he's never been able to get a girl to give him the time of day. All of his friends and coworkers have girlfriends, some are married, and some might even have kids. And he thinks to himself, "Y'know, I did all the stuff society said I was supposed to do. I went to college, got a good job, got friends, got hobbies, exercised, put myself out there, but ladies still won't talk to me. What's up with that?" This self-perception that they've done the "right things" is often false, but not always. This is another thing that I think people overlook. If we believe in allowing people to date or not date whoever they want (and I do), that means you can do everything "right" and still lose. Lack of success does not prove lack of effort.
We don't live in a just world. Your ability to get a girlfriend has nothing to do with your moral character, and women aren't avoiding certain men because they can "just tell" he's a bad person. Crack addicts and chronic abusers have girlfriends. I'm not saying women ONLY like jerks, far from it, I'm just saying that being an upstanding citizen is demonstrably not a requirement. And when you look at those people and think to yourself "I may not be perfect, but I'm not worse than THAT, and yet I'm still alone", it can sting pretty bad.
Not only that, but there's a strong argument to be made that women have most of the advantages in modern gender dynamics, both legally and socially. Legally, a woman can leave you at any time, and take the kids and half your shit, plus alimony/child support. She gets bored of you in ten years? Tough shit buddy, should've been born psychic. Women can also call sexual harassment over anything or nothing. Actually manage to have sex and she regrets it afterward? Made a slightly off color joke that your female coworker took offense to? The large majority of the time the world and courts will Listen and Believe, and your life is over. Now, of course, most women aren't psychopaths. But when you're a massive fucking sperg who can barely exist in the same room as a woman, it's not always easy to tell, and you start to ask yourself if it's really worth the risk of getting #MeToo'd.
Socially, there are far more men looking for women than the other way around (which seems odd given human gender ratios, but here we are). All a woman has to do to get a date is exist and not be fat. A man has to have all the things I mentioned about concerning jobs and hobbies and friends, and that's the BARE MINIMUM expectation. I've seen men say "I've got all the things society told me to get in order to be attractive to women" only to be met with "So does everybody else, what else you got?" And while I know what the questioner MEANS, it's incredibly demoralizing to feel like Lucy just pulled the damn football away again.
And if you're autistic enough to say any of this OUT LOUD, oh God, the snap backs. "REEEEEEEEEEEEEEE YOU THINK YOU'RE ENTITLED TO WOMEN'S BODIES! NOBODY OWES YOU SEX! IF YOU REALLY TRIED YOU COULD GET A GIRLFRIEND! IF YOU WERE A BETTER PERSON WOMEN WOULDN'T HATE YOU! IT'S ALL YOUR FAULT! WOMEN DID NOTHING WRONG! REEEEEEEEEEEEEEEEEEEEEEEE!"
This is not hypothetical, I've seen exactly this kind of response to men merely asking what else they're supposed to do to get women to like them. The Incel™ community, on the other hand, responds "Actually, we noticed that too... sounds like you've had some pretty shitty treatment. Hey, do you have a moment to talk about Our Lord and Savior Elliot Rodger?" And another incel becomes an Incel™.
Now you may be thinking, "But Mr. Pants, you're not describing an average incel. This hypothetical person sounds almost like a borderline normie with a touch of the 'tism." Well, you're right. I'm describing nearly a best case scenario incel. Now imagine how much easier it is to fall into Inceldom when you're a NEET living in your parents' basement.
One last side note. 99% of the time, Inceldom™ (and to some degree, inceldom) is NOT about lack of sex. It's about lack of relationship. This is why incels don't see any point in going to a hooker. They don't want someone to fuck them, they want someone to love them. When incels become Incels™, this manifests in extremely unhealthy and sometimes even violent ways, but the core issue is the same.
Loneliness wears you down, and eventually the things that might've sounded crazy at first eventually start to sound less crazy. After all, they say that insanity is doing the same thing over and over and expecting a different result.
