Good piece, and I mostly agree with where it lands, but there's one thing bugging me. That Brinson stat gets flagged with the right caveat here (variance explained isn't the same as absolute return), and then two paragraphs later it's still doing the heavy lifting rhetorically, like it settles the whole stock-picking debate on its own. It doesn't, not really. Ibbotson and Kaplan ran a follow-up in 2000 and landed closer to 40% of the variation across funds being explained by allocation, which is a genuinely different claim than "90% of your return comes from here." I get why the bigger number gets reused, it's punchier, but the argument's strong enough without inflating it.
Also — and this is the part I kept waiting for and never got — the piece rips into Markowitz mean-variance optimization for being wildly sensitive to input error (fair, that's real), but never mentions what the industry actually did about it. Black-Litterman exists precisely to fix this, blending market equilibrium with your own views instead of feeding garbage expected-returns into a black box. Shrinkage estimators too. Doesn't mean the average retiree needs any of that, honestly they don't, but framing it like the field just shrugged at its own known flaw for seventy years isn't quite honest either.
One more thing, smaller but it nagged at me while reading the home bias section. Telling Portuguese investors to go global is the right call, no argument there, but nobody mentions the currency exposure that comes bundled with it. Unhedged international equities from a EUR base carry real FX volatility on top of the equity risk, and that changes the actual risk profile of the "diversified" portfolio people think they're buying. Would've liked even one line on hedged vs unhedged ETFs, because that's exactly the detail that bites people later when the euro moves against them and they can't figure out why their "safe" allocation is behaving weird.
Anyway — still one of the better breakdowns of this I've read. The risk capacity vs tolerance split alone is worth more than most of what gets written on this topic.