Aside from the impending disaster about to spill over onto three young foals. I think it's the most novelty rather than qualification.
That said, a lot of alicorn princesses seem to take up foalsitting before becoming major powers in Equestria and beyond; is this a running trend or legal qualification to be royalty? If so, what do the male ones have to do? Delivery jobs and football? Celestia forbid...
Hehe, true enough. By who wouldn't want their Moon Goddess to babysit their kids, so long as the foals aren't scalded and given third degree burns?
I'm thinking its a hobby, someway to reconnect with one's childhood centuries ago. As for male alicorns, meh; I won't spend fan speculation on them until we see on in the series. *Hasn't seen the Season 3 premiere yet*