Eh, if they're worried about overwork, the free market will sort that out. As for their society - the Amish are awful insular. Orthodox Jew sects can be insular, as well as Mormon groups. It's not hard to seal yourself off quite well in the modern world, and given that even your most mediocre Hogwarts graduate could command millions (it's magic, after all) they can afford excellent security.
I don't doubt that wizards could make up a ton of plausible-sounding excuses to maintain their apartheid.
You were describing (some part of?) what you think the wizards owe to muggles in order to maximize utility-- you weren't just saying that the wizards should integrate into muggledom.
ETA: There is now a third thread, so send new comments there.
Since the first thread has exceeded 500 comments, it seems time for a new one, with Eliezer's just-posted Chapter 33 & 34 to kick things off.
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