I'm going to defend the costumes of the 2000 miniseries.

Take a look at Macaroni fashion. It's an attempt by the nobility to outdo each other in ridiculousness. The joke of "Yankee Doodle" is that by putting a feather in his cap, that's enough for the yokel to think he's doing Macaroni fashion.

Marie Antoinette apparently once showed up to a party with a boat on her head.

This was a time when the nobility of Europe would reach its peak opulence. Just before the French Revolution started chopping off their heads.

That's what the Dune 2000 costumes are about. A nobility that had gotten too damn comfy in its fancy chair.