It's obviously a joke that is alittle old,worn out. I'm not a goth,etc.. or anything but do like some black metal cds. If you expect people to take it serious that is pretty ridiculous. It's a genre that should be mocked,joked about. Most people will not take it serious. It's not hard to understand the 'black metal' genre so that's not the problem. Someone should not be written off or called stupid if they honestly do not like the genre making fun of it. People taking it serious,being assholes,etc.. will turn people away. If you can joke coming to a realization it can not be taken seriously than someone can look at it with lower expectations. Maybe even forget about the image.
I don't think 'black metal' plays a role in metal where somone's metal credit should be written off because they pick on black metal. There is more to metal than trying to be kvlt,TROO, telling people they should get out of metal because of one closeminded genre.