"you must have at least some gold in your portfolio" – as in...

"you must have at least some gold in your portfolio" – as in owning gold... the physical, yellow stuff. As you noted, it's very stable in capital value. You don't buy gold for a return on investment because it just sits there, staring at you. It doesn't produce anything. There's a relatively constant increase in demand for gold over time that is reasonably well balanced by the constantly increasing supply as more of it gets dug up and sold.

Any other form of "gold in your portfolio", such as gold explorers or producers, is basically just more of the same risk that you already have in the rest of your financial and share portfolio. Every company is just as tied to the global financial system as every other company. WAF pays its workers and suppliers using currency it obtains from selling gold. If the global financial system goes down in flames then WAF is going down with it.