I like the comparison to the XFL. Also, the jab at the “popularity” of XFN is funny.
Leigh does a great job of recognizing the pros and cons of XFN. Although the tools and technology for using FOAF and other metadata are still in infancy, they will arise as the standards are hammered out.
Look at the CSS standard. After all these years (an aeon in Internet-time) the masses are only just now awakening to the possibilities that it brings (hey world: it’s more than just changing the link color on the hover state). Interesting implementations and usable tools (with a dose of evangelizing) are introducing the revolution.
Part of the FOAF spec is lighthearted, but the work itself is serious. XFN seems to me to be more like a fashionable trend.
But it never hurts to look at things from a different perspective and a little good-natured competition may be good for everyone.