Firstly, the problem with this (article's) approach is that if you are a financial adviser and the portfolio falls 5% in a month or a year and your client asks you why how would you explain? Imagine the digging attribution involved.

Secondly, your client's gonna feel that you are no clever than himself and would discontinue advisory relationship with you if all you are doing is direct his funds towards world-equity indices. If you can't distinguish between Mozambique and Philippines then there is something seriously wrong.

Thirdly, remember that it is far easier to make mistakes than being correct. Investing in Mozambique when it's apparent that not many are doing that is a low-cost signal to catch.

Finally this passionate passive argument stems from the incorrect belief that equity markets are zero sum games. Theoretically and fundamentally that's wrong.