I actually agree with you; I was just poking fun at the "high price good, low price bad" tone of the article. Notice the author's apparent relief that a few commodities have "managed to stay out of the bear market" because of bad weather and supply problems.

I've found it's more "high price bad, low price bad". Bull markets come with Malthusian predictions and really strong ones with pictures of the fuel lines in the 1970s.

That's the right question to ask. As far as I can tell, the answer is: both - depending on the comnodity. For oil, it is mainly increased supply. For steel, coal, copper and co. it is probably rather a lack of demand.

Oil is a portion of the price of every other commodity. They all require energy to extract/produce and transport.

There's a third option - there's less speculation now that there was before. AFAIK, most commodities can be paper-traded as well - meaning that traders can buy and sell futures that are not physically settled, but only pay out the current spot price. - i.e. pure speculation. Is it possible that speculators stopped betting on the ever increasing prices of raw materials?

Why does decreased demand indicate that something is wrong? Maybe people don't want those particular goods anymore.

Demand is used as a proxy to measure industrial activity.