Being a functional adult takes practice. Nobody "grows up" until they've been responsible for their own actions for several years. Highschools (and to a lesser degree, parents) have largely passed the buck on this one.

If it were up to me people would get voting rights a few years after they get treated like an adult in all other capacities, I don't care if you move one up or move the other back.

Universities should treat students like adults but these people have no practice being adults so it's gonna be messy.