This means that to strive for a structureless group is as useful, and as deceptive, as to aim at an "objective" news story, "value-free" social science, or a "free" economy. A "laissez faire" group is about as realistic as a "laissez faire" society; the idea becomes a smokescreen for the strong or the lucky to establish unquestioned hegemony over others. This hegemony can be so easily established because the idea of "structurelessness" does not prevent the formation of informal structures, only formal ones.
There's strong structure with holacracy. There's a hierarchy of roles / responsibilities. It seeks to mitigate parallel informal power dynamics. Consider reading the book.