I'm going to explain the reason that I'm a semi-active investor by pointing out the issues I have with two approaches to passive investing; 1) put all of your money into a broad market index fund like VTI, or 2) put your money into an asset allocation fund like VGRO.

Option 1 is purely growth oriented. It's fine if you are young, can measure your investment timeframe in decades, and therefore have the runway to ride out market downturns. I'm nominally about 10 years away from retirement, and my runway is limited, so I choose to stabilize my port by having growth, value, and income oriented investments in more or less equal measure. The market cycles between these three types of investments, so having them all stabilizes the portfolio.

In regards to Option 2, I have have yet to be sold on the value of international diversification in index funds. The growth and value parts of my portfolio are invested in the US, and the income part in Canada and developed international. I'm not even sure what is the point of having an emerging markets component when it's such a small percentage. Finally, a bond fund component would just be dead weight (or worse) in a portfolio right now.

I don't want to diss Millionaire Teacher / Couch Potato because it's a great way to start thinking about the market, but it has limitations. It more-or-less works in a bull market and if your investment timeframe is decades long. In addition, MT didn't foresee market conditions under which bonds would just suck as an investment.