Because for every art-deco-via-disco costume like that killer dress, there's another--albeit accurate--early 80s disaster like this one:

You can't tell, but Chloe Sevigny is actually talking to wardrobe in this shot, like 'Really? My stretch, sequin boob tube also had to be rainbow striped? Thanks. '

Anyway. The whole movie will generally make you glad you were not present for this era, its horrifying music and fashion, or in a movie theater where this film was playing back in 1998.