Is your only evidence for this:
Most importantly, going meta often a mistake when trying to solve real-world problems. Going meta again is almost always a mistake.
This?
To be concrete, when I work as a lawyer, the actual meaning of the rules is usually the only important level of analysis.
It seems very plausible that going meta would be particularly unhelpful in a field that's all about negotiating --and ensuring compliance with-- precedent and explicit rules. Compare to a field where the problem that needs to be solved is one caused by precedent and explicit rules.
My main point was that meta-meta level (the part you didn't quote) is very seldom useful in solving problems. My sense is that Will is too willing to go to that level.
I don't agree with your point about what the practice of law is like, but that isn't important. With certain types of problems, one level of meta is useful very frequently, with other types of problems much less so. It depends a lot on context. In particular circumstances, I think most thoughtful people could come to agreement on the usefulness of meta level analysis (i.e. policy arguments). But Will is particularly poorly calibrated on the usefulness of meta arguments. Most of society under-relies on meta-level analysis. Will seems to over-rely on it.
One of the sharpest and most important tools in the LessWrong cognitive toolkit is the idea of going meta, also called seeking whence or jumping out of the system, all terms crafted by Douglas Hofstadter. Though popularized by Hofstadter and repeatedly emphasized by Eliezer in posts like "Lost Purposes" and "Taboo Your Words", Wikipedia indicates that similar ideas have been around in philosophy since at least Anaximander in the form of the Principle of Sufficient Reason (PSR). I think it'd be only appropriate to seek whence this idea of seeking whence, taking a history of ideas perspective. I'd also like analyses of where the theme shows up and why it's appealing and so on, since again it seems pretty important to LessWrong epistemology. Topics that I'd like to see discussed are: