I'm not going to comment on the Age Policy here, though I'm the one who is currently in charge of the Age Exception process. I will say that younger-aged moderators pose a series of different challenges, many of which we aren't well-poised to deal with. Furthermore, troublesome people who cause issues for the community are MUCH more difficult to get rid of once they are within the staff, so we would prefer to prevent personnel issues before they have a chance to arise; if this means we have to deny at-risk demographics such as younger people, so be it.
But I am vehemently opposed to this idea of an MCSG mod shortage. According to our staff document listing, we have 157 moderators currently on staff (the number may be slightly more, considering the recent hires since the document was last updated). To compare, other communities of our size or larger have only about 80-100 mods. As I stated before, the Sr. Staff wouldn't have chosen to stop all mod applications if we thought there was a shortage. So Taco is correct with his reply:
All I am going to say is that we have the moderator numbers to field a high number of moderators, but pushing for even more for the sake of having more is going to be a disaster. Instead of pushing for quantity and only quantity, the Sr. Staff agrees to turn our focus towards hiring and training quality mods. That's why we feel justified in shutting down moderator applications in an effort to better our current standards.