I declined more than a few invitations for a private league because I don't feel like an additional match in a week. Adding a youth squad might be too time consuming for many of the managers...
Yeah i agree, it should be optional to have a youth team. A lot of managers would find it too time consuming. But, theres also managers out there that want the additional experience of training people up. And most likely they are the people that will stick around with Buzzer Beater the longest.