I don't think you understand the context of this discussion. As I explicitly stated, "there are other ways to address interest rate risk with bond funds." But this isn't a technical discussion about bond buying strategies. This is a discussion about high-level financial "advice" that was woefully inadequate for the intended audience (retail investors).
To highlight this, I used the author's lack of distinction between bonds and bond funds and the most simple difference between how they function as employed by your average retail investor. You're obviously free to go off on a wild tangent detailing in more depth the way that bond funds can be used, but ironically you're only proving my original point: this is not nearly as simple as the OP's advice ("buy a bond fund!") and requires an investment of time and effort that exceeds what the vast majority of people are willing to put in.
To highlight this, I used the author's lack of distinction between bonds and bond funds and the most simple difference between how they function as employed by your average retail investor. You're obviously free to go off on a wild tangent detailing in more depth the way that bond funds can be used, but ironically you're only proving my original point: this is not nearly as simple as the OP's advice ("buy a bond fund!") and requires an investment of time and effort that exceeds what the vast majority of people are willing to put in.