The less an investor pays in fees, the more return there is left to the investor. That is arithmetic. On the other hand, there will be some active strategies - call them factors - that will be favored over time. One's ability to pick (1) the correct factors (2) at the correct point in time is not an arithmetic proposition, but a probabilistic one. Given the amount of skilled professionals out there, those probabilities have gotten slim that a strategy will consistently outperform, or that an investor will consistently pick it at the right time. So, it makes sense most of the time, for most of the investors (including, honestly, many so-called professionals) to simply take the arithmetic bet rather than a probabilistic one where the expected return is less than a draw (due to fees and other frictions).

One thing we can be reasonably sure of, however! If indexing becomes the majority of invested assets, it will again create profitable opportunities for activist investors, at which point active strategies may again come back in favor.

This hedge fund guy can lament all he wants about the timing, but the fact is no one forced his hand, and it was the luck of the draw - hence the probabilities and the less-than-a-draw expected return.