If people don't buy a car because of the "owners" image, thats really sad for them.
I used to have an Audi TT, generally percieved as a 'hairdresser's car'.
Well, i couldnt care less, it was my first car and i was really happy with it, if i were to go back in time i ll do the same thing (but maybe the Quattro then ).
Now i have a Z, a 'poor man's Porsche'. But what the heck, I mean, even a Porsche Boxster is considered a poor man's Porsche, and the people usually using this expression are the ones that already suffer to pay the loan for their Vauxhall Astra, let alone that they will ever be able to buy either a Boxster or a 350Z.
About the image of the guys(and gals) on the forum. If i go to a forum, i go there to get the necessary info on the car. I also signed up here before actually buying the car. Of course there is a lot of "inside jokes" going on, but thats on any community, and the few i know where it doesn't happen because of strict moderation enforcements get pretty boring to read very quickly. Personally i am a member of a motorcyclist's forum, with more visitors and posters than this one, and there is NO moderation whatsoever going on, and it works pretty well i must say.
Oh, and, the average car owner of any type is not the one you will find on a forum. No matter what make/model/... most owners aren't "fanatics" about their car, whether that be a Fiesta, a 350Z, a TT or a Porsche 911 Turbo.
Just my 2 (euro)cents