Unfortunately, they sure do.
Can't beat a bit of casual bigotry, eh?
I have an ex-Amish friend. Seems one of their customs is also to let all children coming of age (I believe at age 18) experience the modern world outside their community. They have 1 year to experience everything and then they go back home. They then decide whether to accept the Amish traditions or not. If they don't, their families will not have anything to do with them anymore. They won't even sit at the same table to eat with the family member who becomes part of the modern world.
Bullsh*t. Any Amish who decides not to accept Amish traditions after their time ‘out in the world’ is welcome back as a visitor at any time. The whole point of the Amish is that they believe only an adult can make a commitment to god (unlike Catholics, who feel the need to indoctrinate their children as early as possible). If their child/brother/sister/cousin doesn’t want to commit to the same god as them and so does not want to be baptised, Amish will accept that decision and not hold it against the person. The problem comes when somebody does decide to be baptised and subsequently turns their back on god, in that situation Amish will turn their back on that person.