I get it, but I think the only reason why you don't see people dancing-dancing to metal, rather than heabanging and moshing, is tradition, not the music itself. The music itself has eminently danceable components, particularly oodles of rythm.
To give a few examples, I can imagine, in my head, wild rock 'n' roll dancing, of the kind you'd see young folks of the '60s dancing to Great Balls of Fire and the like, but this time under the sweet sounds of Motorhead or ACDC and it doesn't look out of place at all.
Anyway, I don't think modern dance is much closer to traditional dances either.
To give a few examples, I can imagine, in my head, wild rock 'n' roll dancing, of the kind you'd see young folks of the '60s dancing to Great Balls of Fire and the like, but this time under the sweet sounds of Motorhead or ACDC and it doesn't look out of place at all.
Anyway, I don't think modern dance is much closer to traditional dances either.