[dasil003]

There's another dichotomy: abstract vs concrete. The more abstract, the larger the potential audience. That's the reason why Joel is so much more popular than the guy writing about OCaml optimization techniques for numerical analysis.

But writing about generalities is not only hard more open to criticism as you suggest, but they are also harder to come up with because they require more condensed knowledge. Coming from that perspective I can understand why Joel says he has nothing more to write about, and I think it's reflected in the quality of his posts recently.