A manchild is essentially a man with means (or who has the potential to earn a decent living) who focuses on himself instead of on women and starting a family. Such a man is seen as selfish and immature. And this is because the default expectation is that he should settle down, get married, and have children. His money isn't seen as belonging to him, and his happiness isn't taken as a priority. People instead think about all the women out there who could take his money and spend it on themselves and their happiness. But can't because he's too busy spending it on things he wants to do.

According to at least one article about this, some of the signs of a manchild include,

  • "Talk of children or commitment brings panic to his eyes."

  • "He avoids serious conversation" meaning he changes the topic when you try to convince him to marry you or have kids with him.

  • "His interests and friendships carry a middle-school vibe." In other words he likes to have fun instead of getting serious about that marriage and children thing everyone wants him to do.

The default, gynocentric view, is that this is harmful to women. That these men who are living their lives for themselves, and not for women and children, are doing something wrong. And the articles you see about this definitely take that approach.

The message is that a proper, mature man does everything he can for women. Including handing over his money so she can live in a big house, possibly have kids with him, and then not have to work a job anymore.

Society condemns and criticizes men who don't do this, which I don't think is fair. If women are strong and independent then we shouldn't be shaming men into being providers and "good husbands" for them. Let him have his hobbies and spend his money how he deems appropriate. A man's time, money, and energy do not belong to women. And if you want to talk about being selfish, that expectation itself is what's selfish.