Wow, very informative; thanks for posting!
The use of different materials was an unfortunate consequence of Chinese manufacturing laws which require a certain amount of the materials for production to come from domestic sources.
Badda bing! This is exactly what me an S133 were getting at. Why use China when they have those laws? Frankly, I think it's stupid; since quality is so important to LEGO, why take chances? Why not use Norway, England, or some other country in Denmark's immediate vicinity to assure quality? China deters me from purchasing items like the pirate and castle battlepacks, items I would have bought if they were Danish, and not Chinese clothes-hangar plastic, i.e. pirate battlepack redcoats that are semi-translucent.
When I see "Denmark, Hungary, and the Czech Republic" printed on the side of the box, I beam with joy. When I see "Mexico," I could go either way. I haven't had any real problems with Mexican parts to my knowledge. When I see "China," I go "Uh-oh..." Nothing against the Chinese of course, but we all know about infamous Chinese plastic...