Why Katherine wants to kill all the vampires?

I don't know but think she wants to kill all the Vampiri#From Dracula to Buffy... and all creatures of the night in between. cos.. She wants to kill them so none of them come in her way while she is making plans to mess around with Damon, Stefan and Elena. She probably at the end wants to kill Damon, Stefan and Elena as well but wants to play with them first. But seriously i reckon we're gonna find out successivo season.. She is obviously going to explain her plans at the end o something, but im just guessing, i don't know for sure. <3

I think the other Vampiri#From Dracula to Buffy... and all creatures of the night in between. are angry with katherine cause she didn't help them to come out too and maybe they want to kill her and she just wanted to be careful, I mean 26 Vampiri#From Dracula to Buffy... and all creatures of the night in between. could be dangerous for katherine^^