The problem is that even with that work ethic (which I don't believe was as prevalent as it sounds), people are literally used as slave labour in other parts of the world. It's not like the cars got cheaper, the rich fat-cats just pocketed more of the money than before. It was a really stupid plan because it was the opposite of what Henry Ford's hugely successful plan was. What these companies did was weaken the financial positions of their would-be customers instead of increasing the likelihood that their customers would be able to afford their products.From what my father-in-law told me, and from some of what my current colleagues do, I'd say its more of a misguided sense of entitlement, in essence, "lets go get paid to f'off all day long because no one will notice". It seems to be a lack of a solid work ethic.
In some respects, I cannot blame US companies for shipping jobs overseas to places where it sounds like the work ethic is the diametric opposite of that in the US. And now, that companies have shipped their jobs overseas, probably many of the same people with the same work ethic wonder why their job was shipped overseas.
The American companies treated their workers like $hit and had no loyalty to them so why would their employees not respond in kind? Just look at how Honda and Toyota treat their workers and it's not a shock that Toyota sits at the top of the world with Honda not too far behind.
As for the Americans and their great idea, now look at them. GM is in a hole that they'll probably never get out of, Chrysler is literally being tossed around like a hot potato by European makers and only Ford seems somewhat stable. The theory that you put forth has been debunked by what actually happened as a result of it.