One element worth mentioning in the debate is maybe age. What I think you will find is that SJs, compared to other types, on average have less diverse music tastes and less appreciation of eclectic music. The thing with varied music taste is probably mostly a J/P thing. All the people I know with the broadest music tastes are Ps, at least. That is also an element that will lead to less average appreciation of metal music among SJs than other types.
I'm not sure about this, although age is certainly a factor - let's face it, most older and middle-aged Ps probably don't like metal either.
As for Ps being more eclectic in their tastes, it's possible. However, I've found some NTPs can be very dedicated to one kind of music. My INTP boss only liked classical music and opera. He had no interest in jazz, rock, world music, folk, R&B, etc.*
My husband and I (one P, one J) have pretty eclectic taste in music, although neither is fond of metal. However, we both like the genres above marked *
We caught a great music show last night on CMT called Crossroads, which paired Sara Evans (country singer) with the lead singer from Maroon 5. The night before that, it was Alison Kraus (country) with Robert Plant (lead of Led Zeppelin). Both pairs melded nicely.
I adore watching Austin City Limits and have rarely heard any group I didn't like. But they don't do metal.
Jae Rae