By Default
This is the hardest to figure out. I can't think of a time when I've heard two Goths arguing over whether or not a band is Goth or not. You hear people arguing that is or that band is popgoth, drock, ebm or darkwave, but not goth or not. Why? Do we just know? And if that is it, how? There must be a way. That is why I don't think it is by default. We would disagree more then. If it were up to individual Goth there wouldn't be a scene, all the music that we liked would be Goth, and everyone has different taste so there would be huge fights over whether or not Smashing Pumpkins are Goth or not. Be all the Goths i know agree that they are Goth-friendly, none would say that they were.

Fashion Alone
Very possibly. But Goth isn't THAT shallow. Fashion is important, but not that important. The way a band looks does play a huge role in whether or not a band is considered Goth. But I don't want to demean myself in to thinking that i like a band JUST because they wear all black. And then you have people like Johnny Cash who always wears black, and he isn't Goth. Moody and dark but not Goth.

Is That a Minor Key I Hear?
If this were the one and only way. Dear Lord would there be a whole lot of Goth bands. Turn the radio to any puesdo-alternative station and you will hear smarms of darkly chorded music. The Dave Matthews Band has many a darkly chorded song, but i would rather die than ever say that they are Goth. This is important though. I don't ever remember hearing a bright and happy Goth song. This is definitely an important aspect of Goth though.

I'm Depressed
Most of the Goths bands i have met, have had a very keen sense of humor. London After Midnight, although complete and utter dicks, were pretty funny. Daniel Ash was laid back but not at all melancholy. He talked a lot about drinking. But i think that is what most Rock Stars do.

In Closing
It takes a little of all of it to be Goth. To quote Virgo (ODK's producer) "to be Goth just takes playing somewhat dark music and having a Goth find it and play it to all of their friends and calling it Goth, then it is." I think that is a little over simplified but he's not that off. Everyone has their own take on it. No one will ever be able to exactly say what IS Goth because it has so many variables in it. For such a small musical genre it has lots and lots of sub-genres. To a Goth there IS a difference between Death Rock and Goth Rock, EBM and Techno-Industrial, Ethereal and Ambiant. So in conclution, Goths will listen to others that they respect, and if a Goth tells another Goth that it is Goth, and they think it might be, then it just might be.

Which is why ODK doesn't take offense to be called Goth by Goths. It is a compliment, even if we don't think we are.