There are complaints every year from the fashion elite about people not sticking with the Met Gala theme. This year, the honoree was Rei Kawakubo/Comme des Garçons. To put it simply, Kawakubo's pieces are extremely unique (see above). They defy both beauty standards and in many cases gravity. It is the type of look that you either nail or fail at miserably.
As with past years, the theme is a tall order and some people decide to just go with what makes them comfortable. It is definitely fun and strongly encouraged to stick with the theme. When else can you take a major fashion risk and have a great chance of ending up on a best dressed list? I do not fault those who choose to go in a different direction though.
I am probably in the minority with this sentiment. That being said, my best dressed list includes both. Those who stuck with the theme and those who just look stunningly fabulous. Neither is wrong in my opinion. That's what fashion is all about.