Any one who has performed knows that any sound you hear when you are onstage refers to you, no matter how your mind tries to convince you otherwise. Any "Boos" heard by the corps, any corps, hurts the kids on the field, even if the boos are actually intended for the judges. Indifferent applause speaks louder and hurts less.
That said, I've heard tales that the riots that occurred at the original Rite of Spring premiere might have been staged by plants in the audience for publicity... not sure anyone would get the joke.