I must admit, there aren't many people (I've met) that don't own a Brompton that then see one and don't think it's pretty neat.
The only people that tend to put them down tend to be those that have bought another bike and put down Bromptons as a way of justifying their own purchase.
I owned three folding bikes before getting a Brompton so it's not like I wanted one above all else. In fact, the first three I chose were deliberately done just because they weren't Bromptons. I genuinely don't care what other people ride, though I am interested in their reasons for choosing their bike, but to make a blanket statement about all Brompton owners is insulting at best.
And I'd hardly say any small-wheeled folder is a fashion icon. They are all, to a point, function over form.