The whole goth guy/ alternative look point misses a significant part of the appeal. People (particularly men) who prominently display membership in a subculture often have a strong sense of self. This kind of self-confidence is generally attractive to women, so those who aren't immediately put off by his group identity are likely attracted to that confidence and the charisma that goes with it.

Practically, this means that alternative styles only tend to work when they're genuine and you're comfortable with them. Someone who feels most natural in more conservative clothing may actually hurt themselves by trying niche appeal, because they need to belong to that niche.