I've been having these conversations for almost thirty years. Even now fairly regularly with my partner, who dismisses anything metal as "angry music" (and only partly with tongue in cheek). I've always found it amusing and frustrating that people can't see past "angry" or "loud" to hear the melody, the musicianship and the story-telling that lies underneath.
An interesting recent example: last night's Commonwealth Games closing ceremony was in part a showcase of all of the musical styles that have originated or been popular in the host city of Birmingham. The show's two brushes with metal were perfunctory given what the genre owes the city. Black Sabbath closing the show was quite welcome, but the tribute to Judas Priest was so neutered and tame that any elements of Breaking The Law were barely audible. You could tell that the inclusion of both these bands was grudging at best.