Well, it's usefull if you think knowing your lat/long in degrees.minutes.seconds is helpful. This has to be moved to the correct location on a paper chart. Before this type of GPS came along, people did this from sextant sightings, and when closer to land, converged directional bearing sights. Then loran. This type of device was a god-send until plotters came along.
For most people that use their gps plotters for near-shore piloting, and not blue water navigation, this would get old. Most just want to look down and see where they are on a moving map.
Chart-based navigation and piloting is becoming a lost art.