First of all, anti-natalism is a moral opposition to reproduction, not a fear of growing up, or of commitment, or of taking responsibility, and not even necessarily a reluctance to have children. There may certainly be anti-natalists who have some desire for children of their own but by virtue of their moral opposition to it, have decided not to produce children. There is no connection between our personal desire or unwillingness to have children and our moral outlook. Reluctance to have children is called childfree, not anti-natalism.
Second, many times it is exactly the opposite. It is people who want children and despise those who don’t want children who are cowards. They are afraid of taking responsibility for their own lives. They are afraid of meeting themselves, of facing themselves and life, so they pass the baton to someone else. They create another person and live their lives through that person’s life. They have nothing in life so they create someone and make them the center of their world. Because in itself, their world is empty. And they are afraid of it. They have nothing to live for and are too cowardly to look for a reason. Instead, they outsource. Parenting arranges and organizes their lives. Without it they would be completely lost in a world where they have no meaning in themselves. Parenting gives them a reason to live because they can’t find one on their own. Or they didn’t look for one at all out of laziness, or cowardice.
People who reproduce are afraid that without children their relationships will fall apart.
People who reproduce are afraid that there will be no one to take care of them when they are old.
People who reproduce are afraid of loneliness.
People who reproduce are afraid of feeling meaningless.
People who reproduce are afraid of feeling insignificant and unimportant.
People who reproduce are afraid that otherwise they will have nothing to live for.
Another thing that people who reproduce are afraid of is being and feeling different. Since the default, especially in pro-natalist countries, is to procreate, there is a social price to pay for those who refrain from reproducing. One of them is a stigma that sticks to people who choose not to reproduce, for example that they are afraid of growing up, afraid of commitment, afraid of responsibility…
The basic assumption is that if someone chooses not to reproduce there is something wrong with them. Either there is a physical problem or there is some psychological problem. This is the default, and some people are afraid of such an image. Others are afraid, as mentioned, of being different or of being perceived as strange. That’s why precisely those who oppose the status quo and are ready to pay the social price that accompanies it, are not cowards but the opposite.
People who claim that people who don’t reproduce are cowards are afraid of change. They are afraid of challenging the status quo. They are afraid that something in the natural order of their world will be shaken. They are afraid they will have to think.