I don't fully agree with the paper but I think there are some very valuable stuff in the paper.
As a market speculator myself, I agree that for average investors, focus on long term appreciation with a wide diversification is the only strategy to win. This kind of "non-active" game is probably most suitable for average individual investors. It is also very important to note that in this game, 99% of professionals are not better at all than ordinary individual investors.
To further rdeduce risks and improve returns, one should play a balanced game between bonds and stocks according to the macroscopic economic conditions. However, to do this, you got to have profond knowledges about the economy. You also need years of experiences in the market. For example, a few months ago, it was good time to sell bonds and accumulate stocks. It isn't yet too late to do so in the next 2 months. Switching between bonds and stocks according to the economic cycle is so far the best strategy for long term investors.
In one word, active fund management is a game for those really brillant individuals. For most of average fund managers, sticking to the index is the only way to keep their job.
For many individual investors, "active" also means "dead".
One thing I noticed in recent years is the increasing involement of news media in the market. Even the governmental data itself shows some artificial traces. All they do is trying to influence the market. Market manipulation is also becoming more significant these days.