That's true, but it also seems kinda irrelevant to the OP (the link happens to be the 1st result for a google search of "us average iq"[1], so I think it was just a quickie cite to back up a statistic). Average IQ people (e.g. the welders and bank tellers) don't seem like they're in demand for high-demand knowledge-work jobs, so retraining is probably not the answer to any economic woes they're experiencing.
Exactly. I have read over and over that US IQ rates tend lower than international. The point is it's even worse to try to train up US citizens to jobs requiring higher cognitive capacity.
[1] https://www.google.com/#q=%22us+average+iq%22