They draw that protection from the fact that they live in a cohesive group in a well-defined (though not, as far as I know, legally set) region. They are welcome to leave, but they would lose the special legal status that the Amish enjoy, and they would then be basically unable to practice their traditional lifestyle.
Are they being kept in a ghetto? Is it by our demand or theirs? Is it reasonable, if we give them their own laws, that we restrict that to a well-defined area?
> I'm looking at a handful of such comments (which call for Jewish presence as cash cows, mostly) across multiple centuries, and an avalanche of comments, texts and laws saying "get them outta here. okay, maybe let them stay this year if they pay more."
How often were they actually expelled?
> What newspeak!
You are cherry-picking facts in the extreme - the "problems of the 1940s" (you mean othe holocaust? What newspeak!) did not just pop out of nowhere, pogroms as ruler-sanctioned way of making a quick buck were a time-honoured tradition spanning the Middle Ages.