That the article is fundamentally flawed in it's assumptions is unfortunate.
What the Chinese do is to substitute labor for capital. Humans are wonderful in terms of how adaptable they are. Plus, we're talking contract manufacturers who are notoriously resistant re: making investments on behalf if fickle clients.
However in the US, labor is substituted with hard tooling, especially at iPad manufacturing volumes. Us mfg labor per the BLS is only $16/hr and $24 with bennies.