It's a little enthusiastic in its point about there being no evidence that active management can be successful, even in the paper it cites. One of the difficulties with points against active management from research papers or e.g. Buffett's public bet is that the entire industry as a whole is often assessed, not just the outliers consistently capable of beating the market. The firms that can consistently beat the market exist in an entirely different strata from the rest. There are fair arguments against their ability to perform consistently, but a more honest analysis would follow the relative few that have evidenced success in the past. Otherwise they conflate "most active managers are not successful" with "the industry is based on a fundamental fallacy."
It's probably easy to read this and overlook the fact that while rare, there are indeed active managers who make their clients far richer than they are when they start, sometimes extremely so. These managers and their firms more or less quickly become richer than the dreams of avarice themselves, along with all the celebrity that comes with. It's not hard to find people who beat the market consistently - the real magic is finding them before everyone else does and prices you out of investing with them.
Finally, for the most part truly successful active managers work with institutional investors, for whom "where are their yachts?" is not necessarily a coherent question. The customers of hedge funds who become very rich are not necessarily going to indicate this in a visible way. The legitimate argument raised by the article and the corresponding book should probably have a more modern question used to convey its point.