Why would you care enough to drag Britney when she clearly doesn't really bothers if her album sells 50 copies or 100k? She probably doesn't even know what day of the week is and probably wants to retire asap.
It's pointless.
But she is a vocal legend, while no one knows/cares about Ke$ha who is trash.
Vocals is the only thing she's known for (+ that cover)
She was being panned + humiliated for her live tour, I mean she was seen as a joke before her death. Her hypocritical ass saying "crack is whack" in her abuser's voice never get's old