Reaction: If the site was "walled" (and not somehow occupied after the builders simply abandoned it), then obviously the engineering skills and social organization for large-scale infrastructure construction did exist.
> The level of complexity associated with these pipes refutes an earlier understanding in archaeological fields that holds that only a centralized state power with governing elites would be able to muster the organization and resources to build a complex water management system.
Reaction: That "earlier understanding" sounds very comfortable and convenient, if you are an archaeologist with elitist social biases, or dependent on support from members of a social elite, or who is a member of his society's social elite. Wealthy and powerful people rationalizing that poor and oppressed people somehow "needed" them was already an old trope when the first pyramid was built.