I think it is reasonable to observe that the current PGP WoT is designed to try to unambiguously and unimpeachably map public keys to entities (if not necessarily literal human beings). It is ambiguous to me in the original text whether the author was claiming that all WoTs must have that characteristic or if he was just describing the current one.

Personally I think this has been a problem with many security systems so far. You can't be 100% confident about anything, so building a system in which that is a fundamental element is doomed to fail. See also the SSL/TLS cert system, in which it is assumed that you 100% trust all the cert vendors in your key store, absurd even before we consider the default key store inflation over the years. If WoT is going to work, it's going to have to have some concept of levels of trust. I'm willing to sign my wife's key with the highest authority I can give. I'm willing to sign the dev I meet at some meetup and who definitely seems to have the same personality and knowledge as the guy I know online with a medium degree of trust. I'm willing to sign other people with low degrees of trust.

Sure, dealing with the consequences of partial trust are difficult. But since you can't have full trust, it is in less difficult than our current systems based on it, inasmuch as a thing that is possible is less difficult than a thing that is not possible.