The thing with Pitti, is that it is self-selecting.

Truth.

I should mention that even the men I encounter who dress like utter rubbish (I often refer to them as the intersection where clueless and classless collide) they all want to talk about clothes, what Im wearing, what people on TV are wearing, what the girl is wearing etc... Thus, even the most slovenly, thrown in the towel clod has an interest in clothes; I just wont discuss it with them.

Even in the California techie community where they profess loudly that clothing does't matter at all the clothing codes are very rigid, with quick and swift opprobrium when you don't conform.
The uniform trouser is jeans, shorts for casual.
Buttoned shirts are for the managerial class, t-shirts for the rest.
From a distance it all looks college campusy until you look close and its a bunch of late twenties and early thirty year olds holding on to the college glory days. Kind of creepy. The guys look pathetic, but the real disaster is the women. Short cutoff jeans covering a flabby derriere are both pitiful and offensive.
Anxiously self-righteous desperate hip.

I always visit my son wearing a coat and tie, just to rile the natives, who invariably ask me if I want to take off my tie.