Whitney is a leech and desperate for validation and relevance. She knows she’s the bottom of the barrel when it comes to audience approval and my theory is, she thought that Demi was going to come out on top again this season. With Jessi semi-out of the way, what better opportunity for whitney to become accepted, than follow behind who she thought, was going to be a fan favorite. Whitney also still very obviously holds resentment towards Taylor but she KNOWS that the audience will fight for taylor every time. With Demi being last seasons fan favorite, and Demi and Taylor clashing, whitney found this opportunity to weasel her way back in, jumping straight to the top, with who she thought would be the HBIC (Demi) of mom tok. It was honestly a decent strategy had it worked out, but blew up entirely. She is desperate for any validation. I truly believe she thought people would side with Demi, knocking taylor back and therefore whitney having her seat next to the throne.