I think the problem is that many twelve stringers are six string players just after a different sound (or volume), without trying to learn to play the twelve string properly. The tuning may be similar to a six string, but the techniques for playing and using its altered voicing is rather different, but so many just play it like a six string, relishing the extra volume and octave notes. As I’ve said before, people are encouraged to learn guitar chords and strumming styles first now, and in the past you learnt scales and fretboard navigation before learning to combine notes into chords.