Perhaps the IndieWeb is growing at such a much slower rate (in this thesis, there is a much higher level for "proof of work") that this sort of social capital is more akin to that of social capital in real life? Some of the value of IndieWeb is that all your "social capital" can be put in one place and better controlled by you.
Why would one want to game their own sites in these ways? Are personal sites a better reflection of real life social capital? There's also lost personal time in learning and participating in dozens of social silos which is much better spent creating things of greater consequence.
With respect to his mention of Paul Krugman's Instagram account, it's useful to be able to pick and choose what you might want to follow in Paul's life. If you're a close friend then his Instagram account is awesome, but if you're a young political science student then his bookmarks, reads, notes, and articles would be much more valuable to you.