I'm probably by myself on this, but truly...I adore ballet costumes. I enjoy tremendously "tutus ballets", and to be honest, I really haven't got to that level of abstraction to say, for example, that I could enjoy "Les Sylphides" the same even without the romantic tutus, for which it would be just as great due to the beautiful choreography. But again, I don't have the Balanchinean background you all have, so I'm sort of outdated on this matters.
In my humble, amateurish point of view, the dramatic effect of many ballets diminishes in a great deal when stripped down of costumes...(I'm fine with the "non-props" segment). If I could watch Symphony in C in its original tri-colored structure, or Ballet Imperial with tutus, or even Concerto Barocco the way it was according to those great pics Peggy posted, I would definitely be more attracted to them.
Isn't ballet, at the end of the story, a great mix of beautiful stories, choreography, music, sets and costumes...?
Couldn't it be that we tend to accept and celebrate Balanchine's eliminations, just because they came from the master himself...?
Would you be just as careless if T&V, Chopiniana, Jewels or Symphony in C would start to be presented in plain tights ...?