I loved this performance and was totally won over by this kick-ass all-female group, which is totally rare in a capella, only to be surprised and saddened when the judges told them they really needed to work on their low end, and that their performance was "too treble". Especially since the judges seemed to completely flip over the all-male groups that may have had lower voices but were all over the place and less in tune.
Now, as a flute player and a soprano who majored in music in college and got a music degree before moving into Women's Studies, I have my fair share of experience in the music world, and I am all too familiar with the hierarchy set up in most musical ensembles in which lower voices are always, always favored over higher ones. The idea at work, which does have some musical validity, is that the lower voices (bass voices in a choir, low brass in a wind band, basses in an orchestra, etc.) provide a tonal foundation to the sound and make it seem fuller and more resonant. I'm down with that. I get it.
The problem with this is that, more often than not, those higher voices in musical groups are disproportionately sung or played by female musicians, which, when coupled with the higher sounds of the voices and instruments themselves, contributes to a culture within the music world in which higher instruments/voices are coded "female" and are therefore devalued, and lower instruments/voieces are coded male and are therefore celebrated.
This leads to a climate in which female singers are told that they are "a dime a dozen" and that there are always too many flutes, and that brass bands and brass choirs are distinguished, percussion ensembles are awesome, and flute choirs and woodwind ensembles are a joke.
I have so much more I could say about this and so many more examples of how this plays out in the music world, but I just had to put it out there that there is a whole lot of subtext to telling an all-female singing group that they sound "too treble".