"Average" is a number, a single number. Either the article is being deceptive by writing a range, or we're not talking "average". Innumeracy - no wonder they can't find skilled workers.

More seriously, Boeing's 787 production problems are an example. Boeing moved production from unionized Washington state to non-unionized South Carolina. Problems ensued. I'm not saying that unions don't have problems, or that they'd solve everything, but if you de-prioritize your labor force, I'm not sure why you'd expect to attract skilled labor.