Look, I’ll say this. Katherine may have said that she loved Damon because it would rattle Elena. But, what seems to confuse people is her behavior in 2x21-2x22 — in comination with these words. Hence, it’s very much a statement like, “I don’t get it! First, Katherine loves Stefan forever (and ever, amen!) and then she loves Damon. Katherine’s confusing!” that tends to circulate around the fandom.
But, I’ll agree there.
She’s an enigma, and I don’t deny that.
That said, I think that what you’re pointing out is actually pretty simple, and just wasn’t told to you throughout...