The analogy is tangential to the book.
The connection being made was that both anarchists and libertarians are sort of walking embodiments of the No True Scotsman problem.
Basically, no anarchist to tell someone else that they are or aren’t an anarchist because they are groups built around not having an authority to tell you what to do (or who you are). The other side of that coin is that the definition of what it means to be an anarchist is owned by each individual in the group, so anarchists often have very strong opinions about who is and is not one.
So the trouble with an anarchist convention is that you can’t decide who gets to come.
