I do not see why people are having such a problem with this. This was not the first time that this group won. I understand that there were several qualification rounds which they had to make it through. They earned a chance to compete, and they brought it.
Besides, and this may get me in some heat, I enjoyed their routine more than the AKA's who clearly had a "type" on their team; i.e., "dark-skinned sisters or sister with naturals need not apply because so much of our routine involves flipping our WEAVES back and forth, from side to side, and staring at our hand incessantly as if it were a mirror."