A riverboat can pull over to the shore at any time on their journey. Try and pull your ship over mid-jump, let Me know how that works out for you all. lol. That is why ocean-going is more accurate, because you are literally alone in the middle of nowhere (jumpspace). I use 17th and 18th century Caribbean as My analog for the feel of how Traveller plays out. Most of your destinations are reachable in a week or 3 of Traveller and you can take any route that you want, unlike river travel where everyone has to follow the same route, but at the same time, once you are out of sight of the shore, you might as well be alone on a different planet.
Also, in Traveller, one week, between stopovers is the minimum, not the maximum or the average. A 2-jump trip is 2 to 3 weeks of travel time where you may not be refueling at a port.