Couple of comments:
(1) Pitti is much more about fashion than understated style. The brands, products shown - and the buyers / attendees as well - reflect that reality
(2) The photos you see are of people whose business often depends on being noticed, photographed, and essentially advertised. The clothing choices they make during these 4 days is aimed towards receiving that free publicity and PR
(3) It's a clique. A couple dozen dudes, a dozen bloggers, constantly feeding off each other. You scratch my back, I scratch yours.
(4) some guys push the envelope but actually look really really good. Not in a classic MC way but still look good. Agyesh (shorter guy with the tulip hat) is a great example of that. He's got his own style, and of course he's in the business of promoting his company's stuff and new designs, but he has excellent taste.
They're the "In" crowd in desesperate need of self promotion to increase their exposure...
Like every clique or microcosm ,they're becoming very irritating quite quickly..