I am quite surprised no one has commented on this; this is a very interesting topic.
Does anybody know if the US ever had the "German apprentice model" (for lack of a better term) in which engineers are expected to apprentice in businesses like machine shops (for mechanical engineers), before one could actually become an engineer? I have read biographies of some of the great German engineers that apprenticed first, then finished their degrees. Of course these biographies took place before WWII, but I think this kind of thing still goes on in Germany and France to some degree--an acquaintance got his PhD from a university in Germany, had to come to the US for a couple of years to get some job experience before moving on to a position back in Germany; I think it might have been a condition to receive his PhD, I am not sure.
I would think we could do a similar thing in the US, easily, by requiring a semester of CO-OP, as long as you could convince companies they really needed to take on CO-OPs! However, it would probably benefit the engineering student even more to have to go work in a shop (mechanicals and electricals) or on a road crew (civils), but I don't hear ANYONE talking about imposing such a requirement.