What makes you think that work is not a part of the human nature? The ancients certainly believed that (cf. the Greek concept of "demiurge" = artisan-god). And how about hobbies, crafts, and volunteering people often pursue?
The fact is that creative work has been hijacked and turned into profit-making drudgery by capitalist bosses. But if I read Marxist critique of capitalism properly, the point is to restore creativity and dignity in human work, not to enforce idleness. Forced idleness is hell (cf. prison).
PS. I do not think that Amish children are being "forced" to work any more than being "forced" to their lifestyle that renouces most of the dubious wonders of modern capitalism. But that is, of course, subject to empirical verification.
wojtek