Well, as a rule, the superheroes around him found ways to be timelessly unfashionable. His own girlfriend's Troia getup, for instance, was never, will never, and could never be in style. With Terry, it's like "look at that poor schlub, he thought that looked good?" The Titans, on the other hand, were clearly never even trying - they're beyond such petty concerns. He should have taken a clue from the company he kept, and eschewed any attempt at style entirely, thereby vastly increasing his long-term dignity.