"Value investors believed that corporate profits and profit margins, which had benefited since 2008 because of declining commodity prices and a weak jobs market, were bound to revert to the mean."

Don't agree.  Yes, lower commodity prices have been a positive for "some" companies....but Apple, Google et al don't care where thermal coal or copper prices are.   The stock market of 2017 is not the stock market of 1952.   The largest companies in the market place are increasingly NOT capex intensive....and tend to generate a LOT of free cash flow, and have much higher EBIT margins than did the capex intensive companies that dominated the DOW etc. 60/65 years ago.


The weak job market has indeed been a factor ....  and the lack of real wage gains (until very recently) has helped profit margins....but it is NOT the driving force in corporate profits it was several generations ago.

And please do not lump all "value investors" into the same sub-set.