If you want to know the attraction of redpill, and the manosphere writ large, consider the differing responses a man having lack of romantic success gets if he were to say, do a mixture of venting* and soliciting genuine, actionable advice as to how he change this ASAP.
1) He goes to conventional sources. "NOBODY OWES YOU ANYTHING!" Whether the guy remotely implied that at all is, of course, irrelevant.
2) He goes to the manosphere. They'll give him concrete steps on how to improve his chances. The advice might be cold and blunt, but most of the guys... genuinely seem to actually want him to succeed, and will congratulate him when he takes those first steps towards improving himself.
It's not hard to figure out which one most of these guys will pick. Half of the stuff on the manosphere is cold, brutal truths that, sadly enough, most young men aren't going to get anywhere else these days. Half of the stuff is rambling idiocy that forgets that women are, you know, human beings with all the random mix of altruism, frailty, hypocrisy, and meandering goodwill. If you aren't a psychopath, you can pick out which is which.