Everyone wants to hire only the above average, pay the average, and complain that they can only fill 50% of their opening...
There's actually a lot of truth to that, in many industries. Take trucking as an example; the industry claims there's this huge shortage of drivers willing to drive trucks. It's a myth created by the industry to get suckers in there to work for peanuts. Just like the quote from the original article with Jay Leno: "If there is such a welder shortage, why hasn't the pay gone up?"
Many skilled trades are going this way, to include low level IT. With globalization, there is no shortage at all. If there was, wages would be going up, not falling off a cliff like they have over the last 2 decades for average workers.