It's just another tool, like a compass, VOR, ADF, Autopilot. Anyone flying a specific aircraft should be thoroughly familiar with and competent in the use of all the bits in it - including all the above. Instructor-induced failures of any / all of these aids is a useful training technique.
Many of the GPA NPAs in USA are actually overlays of previous or existing NDB & VOR Navaid NPAs. There are not that many of the dedicated GPS waypoint-type approaches such as we have designed here. NDBs are programed for phase-out in 2006 (again).