I think both sides of the GPS/anti-GPS fence are correct. The GPS really is the best advance in nav. since the compass. However, competent navigating is more than just following a GPS indication. There are fundamental skills that need to be learnt and blindly following a GPS isn't one of them.
I like the calculator vs. learning how to do addition analogy. Does anyone advocate dropping addition from a maths syllabus now that calculators are ubiquitous?