Their fashion sense seems to be a rejection of anything associated with fit attractive women as a defence mechanism. So they can say "See I'm not trying to look like those girls, I'm quirky and unique" when they really know they can't pull off those outfits which is why they always wear tents. Same with the vintage obsession, those dresses are basically tents. It's a lot like the neckbeards you see at conventions who dress like total shit as a sort of defence mechanism, because they have neither the confidence or the physique to wear fitted and appropriate clothing.