Originally Posted by Holdfast
More unhappily, I suspect it may also reflect subgroup distaste for an up-and-comer/outsider/"foreigner" who tries his best to simply do things correctly but can never fit in because he doesn't understand how to break the rules just right.
From the practical perspective, this.
Dress is a signalling mechanism, even if you "dress for yourself" -- particularly if you "dress for yourself." But, like all signalling mechanisms, the easier they are to "fake" the less valuable they are.
Up until relatively recently -- in fact, up until the invention of the internet -- the finer points of classical dress had to be transmitted . . . well, I would say culturally here, but Fuuma would probably jump all over me . . . anyway, it was something that you learned from your family and from the social mileau that you inhabited which in this case, of course, means the upper classes. Because that was the only way it could be learned, it was a powerful method of identifying PLU and weeding out poseurs.
In that context "sprez" or insouciance or whatever you want to call it was part of the signalling mechanism. Poseurs, or, to use the technical term, "wannabes", might be able to mimic the macroscopic elements of classical dress but they could never learn to mimic the aspects of actually living in those clothes unless they, well, actually lived in those clothes. This is what "sprez" originally was.
To give you a small example. I have a number of RTW OCBD shirts that I wear casually (and when I say "casually", I mean as only we here on SF can imagine the term) that have double-button cuffs. I usually wear a sports watch with these shirts and, hence, I leave the button on the left wrist closest to the hand unbuttoned so the watch can fit under the cuff. Out of habit, I usually don't button that button even if I'm not wearing a watch.
It is this kind of process that generated the idea that pocket squares should just be stuffed into the breast pocket. Wearing a pocket square carefully folded into an origami crane is incompatible with the idea that your pocket square is something that you use. But so, of course, is having a pocket square in expensive silk that features a hand-made reproduction of the Bayeux tapestry or whatever.
Is this all pointless now? Probably for its original purpose, yes. Though the idea of sprez is a useful antidote if we find ourselves spiraling into OCD trying to follow all the real and imagined rules attached to classical dress. But even the signalling mechanism of the suit itself is fading. This may be the last generation where wearing a suit and tie will get you a better table at a good restaurant.