I sort of get what you mean. If a man says that he does not want to have children it gets inconsiderate reactions. But in a patriarchal setting women bear most of the brunt of child birthing and rearing. Men are expected to, I don't know how to phrase it, do the work that is allegedly societally important while the mothers stay at home and look after the children and the home. Deranged republicans abhor the fact that women have the autonomy to reject this sort of setting which is where the shaming stems from. In my opinion.
Let me know if I am being unclear. I haven't talked about this topic before so I don't know how to articulate my thoughts well.