He's not making a comparison to the traveling salesman problem; he's saying the businessperson only intended to visit one city, but the trip ended up requiring

He's not making a comparison to the traveling salesman problem; he's saying the businessperson only intended to visit one city, but the trip ended up requiring visits to several additional cities. It's not a terrible analogy. You request an HTML page and you don't know until after you load it (visit the initial city) exactly what other resources--images, css, js, etc.--you'll need to download (additional cities to visit).