I'd praise Britney if she performed and actually slayed it. It didn't happen at the BBMAs. It sucked. She lip synced, and didn't even do heavy choreographies, so yeah. It was awful!
Mhm, and this happens when Gaga tries to sing live while dancing, right?
It's just that, the expectation for her are exorbitantly low, given her knees, her old age, her battered body and her retarded brain. The performance is sort of endearing cause most people remembered her as the mental, drugged up, loser who shaved her head and dropped her baby. To see her execute those robotic movements are nothing but heartwarming! It's like rooting for the that limp-wristed kid in track race.
Just look at her movement during Work Bitch, you wouldn't call this "slaying" for any normal human. For Britney, it's an exception