So, having found one or two glaring factual errors in the piece, I went looking for more.

I can't easily find a chart of real GDP growth since 1950 from an official source, but I did find the chart on this page - you have to scroll down.

http://www.valueinvest.org/27.html

Look for "GDP growth vs S&P 500 returns", the blue line. This should, I believe, correct for inflation - that's what the whole "corrected for CPI" thing is about.

Interesting things about this graph: national real GDP has been growing, and there is no obvious discontinuity in the 1970s - sure, there was a big recession then, but that's just a jog in the chart. Squinting at the data, it looks like the average rate of growth is about the same immediately before and after the 1970s; if anything the rate of growth is a tiny bit higher since then.

So, either this chart is bogus or the OP is bogus. Having already caught the OP citing false facts about domestic manufacturing output, I have my suspicions. But feel free to cite a better GDP chart; it will be nice to have in the files for when the next nonsense article comes along.