He is talking about companies that enjoy monopoly profits because of superior products: "I'm not interested in illegal bullies or government favorites: By "monopoly," I mean the kind of company that is so good at what it does that no other firm can offer a close substitute."
Distinguishing between "good" and "bad" monopolies is sufficiently complex to deserve more in-depth exploration. Thiel is smart enough to realize that which is why I consider his point to be misquoted. Unfortunately, his view is oversimplified so as to be readily consumed and debated.
He lists characteristics of a monopoly in his book: proprietary tech, network effects, economies of scale, and branding. First mover advantage is mentioned as a "tactic, not a goal" - a chapter is even called "Last Mover Advantage." Google, for one, was clearly not a first mover in the search space.