Sounds like a "nicer" rehash of the Gervais Principle. I haven't read Developer Hegemony, but from the looks of the author's blog, I would recommend "cutting out the middleman" and going straight to the source material: https://www.ribbonfarm.com/the-gervais-principle/
Not at all. Gervais Principle is a joke, though some serious research may have been done around it. It's about organizational dynamics.
https://www.daedtech.com/ blog is (by quick reading of two posts) career advice for software developers. Very thoughtful, very well written and explicit, with analogies, anecdotes, and opinionated advice.
Whether that advice is any good, I'm the wrong person to judge; I still work as a wage slave (: basically he's telling everyone to go out as independent consultant and solve customers' problems instead of being "an entry in someone else’s Gantt chart. If you can’t autonomously deliver value with your expertise, then you’re specializing in the wrong thing."
