I didn't say people need to use a GPS. I said a course on navigation should include coverage of how to use a GPS & UTM grid with a map and a compass. The four devices (GPS, UTM grid, map, compass) work VERY well together and the methods are quite easy.
A GPS is no substitute for a good working knowledge of how to use a map & compass by themelves. All the GPS does is tell you where you are right now. Most also have the ability to provide direction bearings to a destination AND provide as-the-crow-flies distances. The other nice thing about a GPS is that it can help provide direction & distances if the user gets off course while on the way to the destination. Of course a user could create a fairly accurate UTM grid on their own if necessary.
A compass certainly doesn't tell you where you are, it only tells you which way is north. By itself, a compass is only mildly useful.
As you say, by combining a good map with a knowledge of how to read the map and a knowledge of your surrounding area (visual clues), a user can often tell which way is north AND where they are on the map. On the other hand, visual clues are not always available - such as in dessert or flat-land woods. In that situation a compass will tell you which direction is north, but you still may not know where you are. That is where a compass along with a GPS comes in very handy.