The article all but ignored a very large category of active investors; namely the dumb ones who underperform on both time-weighted and money-weighted basis. They include 80% of the country's active managers more or less.
I think the article would have sounded more realistic and maybe disheartening if it had focused on them instead of Mr. Buffett.
I had the honor of speaking to Mr. Buffett once by the way. He was slick and funny.