I think Instructors can be divided into two camps, the traditionalists and the revolutionaries. There are many who want to see the preservation of traditional skills and many of those never teach any gps use at all. Amongst the revolutionaries there are those who would throw out all the traditional teaching and simply follow the magenta line, rergarding a nav failure as an unlikely event to be treated like a stall or an engine failure.
Systems have advanced to the point where they cannot be ignored, in some cases they are a fundamental part of the aircraft and have to be taught. In the absence of any real syllabus change it is down to instructors to ensure that their students are adequately equipped to cope with the wide range of equipments available.
Examiners are required to see the first leg of the Skill Test Section 3 as conventional VFR navigation, after the first turning point, any equipment fitted to the aircraft can be used. Examiners should use this in a practical way in order to assess the candidates ability to navigate and in partricular not to place the aircraft in a position where an infringement could occur.
Much of what you refer to eminates from those dealing with infringers and whilst their arguments are sound, they are not synchronised with those conducting training in often basically equipped aircraft. A pad with Skydemon on the knee may well prevent an infringement, but how you teach someone to use it and integrate its use with conventional equipment is the challenge being discussed at seminar level.