Teen Gothic

I know goth music extends to a lot of different sounds/sub genres and it doesn't all sound the same, but it's not too different than any other genre/sub-genre.

When trying to explain what is/what is NOT goth music, a lot of people get either offended, extremely confused or start arguing against this, as if goth music isn't a real genre of music and/or that it incorrectly extends to other bands/sounds/genres, or that a band/song isn't really goth music, but just a higher genre realm like post-punk or alternative and that the sub-genre goth never actually applies.

Why is this? What is it about goth music that people have such a hard time understanding as a genre?

It's not like if someone was listening to a Mozart symphony and you were like "oh wow, I love classical music so much", the average person would say "what are you talking about, that's not classical, there's no such thing as classical", or that they would say "Mozart is punk."

It also confuses me why so many people insist on calling other genres goth music. The classic examples being stuff like Depeche Mode, etc…

So many people get so defensive about this. They either haven't really listened to what the full spectrum of goth music sounds like, or they have and are confused and just feel the need to argue that certain bands/songs still are goth music when they clearly aren't. It's not like the average person would call Mozart, Jazz music. Why does this misnomer happen so often with goth music?

I get that there are some similarities within other genres that share similar sounds/instruments as goth music, such as synth-pop, industrial, ebm, etc… But anyone who has even the smallest amount of music theory knowledge would/can be able to make the deduction that, if one song/band doesn't have the vital elements/factors of a certain sound/genre, then that song/band won't be considered that certain sound/genre.

I suppose this happens within other genres too, but it seems like this is very big especially with goth music and I can't figure out why this is.

Any thoughts?