M...maybe they revamped Nite Owl's costume on account of: realism is a big part of Watchmen, and - the genres and different media being what they are - whilst a spandex costume works in the pages of a comic, it does not so much on-screen, and audiences need to believe that this guy did actually go out and fight crime with reasonable success for a number of years? Maybe?

*eyes Silk Spectre II*