The article gets into the origin of the term, which surprisingly isn't just a funny turn of phrase the author of the book came up with to make fun of them:

Then a pretty well-known figure from the crypto world reached out to me over DM and said, “You know, we’ve been calling these guys the Nerd Reich for years.” And I was like, “What?” The URL was available, so I rebranded my newsletter as the Nerd Reich and announced it in dramatic fashion.

To me, the most important thing is that this is not a name I came up with. This is a name their own peers use. They are telling people what they are doing. They want people to know because they’re evangelizing to bring in more believers.