We keep assuming that Elena will hate Damon but what if at this point she's been stuck in limbo watching Katherine live her life and is so pissed that she herself is going to be in a self destructive mass killing mood when she gets back?
I mean she could probably be more pissed that no one figured it out in time then about what Damon is doing I can see her saying "Of course Damon went off the deep end that's what he does but guess what? I was stuck on the other side alone watching Katherine live my life while you all did nothing and guess what? I want to go off the deep end this time I mean Damon makes it look fun!"