In many ways, I feel like I shouldn't have to write this, and that everyone should be polite and well-mannered anyway, but the world doesn't work like that, sadly. A lot of rudeness gets directed at us Goths by people who are prejudiced, judgemental, and ignorant of who we are, but sometimes we Goths don't act politely either.
I know that Goth, as an offshoot of Punk, has its roots in a subculture that used profanity, rudeness and shock tactics as means of political and societal protest, but Goth was a departure from Punk, and most of us are not engaged in a countercultural protest, in fact quite a few of us, myself included, are quite keen to point that our dress and lifestyle is not an act of deliberate rebellion, that we aren't trying to be some sort of non-conformists, or acting like this for any kind of audience or attention, but rather that we are just have a different set of tastes and values than the mainstream.
Anyway, when wider society has a negative opinion of us anyway, confirming that opinion by acting rudely does not really shock; it is far more unsettling for us to be pleasant, nice people because then that forces them to confront that their pre-conception was wrong, and depending on what sort of framework of notions about the world that this pre-conception rested on, forces them to confront to some degree the under-pinning ideas. Jillian Venters of the amazing ::Gothic Charm School:: calls this concept 'subversion by politeness' and it was reading her articles that gave me something to coalesce my own ideas about this topic.
If you go out dressed visibly Goth, then people will, on some level, see you as representative of the subculture as a whole. If they associated Goth-looking (and most mainstream people can only do a best-guess at subcultures from appearance) people with rudeness and anti-social behaviour, then it will reflect badly on the rest of us, even those that are not involved - also, people tend to assume that all local Goths know each other (I very frequently get strangers ask me if I know someone specific because that person is also Goth... I'm pretty well connected to the local subculture, but I don't know every Goth between Fort William and Aberdeen!) and therefore if you do something that upsets people, that can have repercussions on other local Goths, or if over the internet, Goths in general.
Being a polite can genuinely change people's perceptions of Goths, or at least the individual being polite. A while ago, before I moved to Scotland, I used to frequent a little cafe with Raven. I went there more than he did, because it was where I was living at the time, and he was still living in a different country! Anyway, we'd still go there whenever he came to visit, and I would go there in-between times for take-away hot drinks and rather yummy cakes. Initially the owner was a bit afraid of me; she saw someone who looked spooky, with a coffin-shaped hand-bag (apparently that was particularly spooky) and all the anachronistic fashion I usually wear, but then, because I was always friendly, polite and cheerful, she realised that I wasn't a scary person after all, just a spooky-looking eccentric, and neither was Raven. Raven and I made it a tradition that on the last day of his visits to me, we would go there for afternoon tea, complete with cakes, etc. and with regular custom began to build something of a rapport with the staff. I think this is part of why people like Jillian Venters of Gothic Charm School and I want to encourage good manners so much; when people assume the worst of you on sight, you have make it very obvious that the worst isn't true, and it can change people's minds about old assumptions.
If it is likely that people assume the worst, then you have to put in a bit of extra effort into making the good parts of your personality shine through, because people's prejudices can blind them. I am not suggesting being fake, only that it is important to take into account how others around you will react, and to consider what will be the most beneficial course of action to all involved.
