This is one of the most sad and ironic aspects of this reality. Men are conditioned to believe they aren't capable of being the primary caregiver, so they let it become a self-fulfilling prophecy. Then, the men that do take up the mantle, are put under a microscope or disregarded completely.
It's an insult to the many devoted dads out there. And an unfortunate perspective that keeps some men from being the fathers their children (& partners) deserve.