I would guess that most new converts are not in a high enough tax bracket to be of great value to the tithing coffers, and so even the GA.s have admitted behind closed doors that the mission program is strictly a way to keep a choke hold on the young men and is of no value otherwise.
As far as rite of passage in the world, which Mormon Missions are, this is pretty pathetic but also goes on way too long. Some Amazon youth put on gloves loaded with stinging bullet ants and have to keep them on for ten minutes. In Vanuatu the young men just bungee jump head first with a vine tied around their ankle and they don't do it for two years. In Ethiopa they have to jump over a castrated male cow four times while naked. Maybe not easy but doesn't take two years of your life.
Perhaps with regard to the missions, the Prophet could take a page from some tribes in Ethiopia. Part of me wishes that had been my rite of passage. The other part of me is glad I got to know another brilliant culture, learned a language. and ate a lot of homemade empanadas
There is likely a lot of truth to that idea that it's for the indoctrination of the young men and to create loyalty. But interestingly I'm seeing a lot of Latin American elders and Asian sisters coming to Utah. I wonder what the objective is there. They are coming with little English skills, from the 2-3rd worlds to the 1st world. Lot's of the young missionaries I've talked to say they plan on staying here. They like America more than Tonga.
I'm guessing Russ wants them to transplant Utah culture and language over there, but they aren't so excited to go back.