"Why do some Amish leave?" is a question I'm asked when on speaking engagements.
While time doesn't permit a detailed answer, this is the condensed version I give:
In my experiences with former and current Amish, I’ve learned there are three main reasons they leave: 
(1) it’s just not a lifestyle they wish to live, they want to live as English,
(2) religious freedom – to grow in their personal knowledge of God, and
(3) they want to work and live beyond the cultural confines.

To explain ~(1), I...