Detroid Diamond theory
I've got a feeling that the reason Detroit Diamond stayed around as long as she did is because it was the producers' choice. They wanted the drama of her performing on the anniversary of her brother's passing, which they just so happened to pair her with BJ the Chicago Kid, who just so happened to be singing about death. It all feels too coincidental to not be planned.
She made it through over Dono, Tia P., and Jaxs with an X, and I would argue that all 3 of them deserved to stay over her at each of their eliminations.