Notwithstanding that the author is correct about the source of volatility drag, or whatever he proposes we call it, the title of this article is "The Myth of Volatility Drag", which implies that some concepts of finance are 'real', whereas others are 'less real' or 'not real'.

As others have already alluded to, given any sequence of returns, the greater the dispersion of those returns, the lower the total return realizable by the investor. This phenomenon is real and directly attributable to volatility.

The author's point is therefore philosophical in nature, as it questions whether volatility is some external force or rather an inherent attribute of the underlying investment. You can argue either way, but that does not change the fact that volatile returns compound at a lower rate than stable returns, ceteris paribus.

This concept is fundamental to investment management and needs to be called... something. You can argue it shouldn't be 'volatility drag', maybe it should be 'volatility effect', but that doesn't change much now, does it?