I don't read him regularly, but I read it as him downplaying index funds as some sort of arbitrary, socially derived benchmark, which just isn't the case. He glosses over - he surely knows this given his background - all the efficient market theory that created the index funds in the first place.

There is a good reason that index funds are very difficult to beat consistently, and it's not because they are copying all the hard work everyone else does for fees. It's because you don't get paid for specific risk.