Cami was Klaus's Conscious
I remember one of Leah's interview way back at the start of season 3. I didnt get it at that time but I get it now, I think
Klaus already knows what is right and what is wrong. He knows he wants to be good for his daughter. He knows that he has to be nice to his family. He knows that he wants Hayley happy. But he hides behind this mask, wanting people to believe that he is bad. He thinks showing kindness makes him weak but we know that he is capable of good. We knew it back when he was in Mystic Falls. But he has never expressed his desires by his own mouth, his desire to be a good father to Hope or wanting Hayley's happiness or wanting to treat Elijah and Rebekah nicely. All of these desires we hear from Cami's mouth. I think she was there to express his conscious to audience and to give Klaus affirmation of his thoughts. Most of the advice she gives him he already knows e.g. the one she gave him about Hope before dying, her telling him "happy mom, happy dad, happy baby" when Klaus had already given Hayley her dream wedding. I have more examples but these two are only from the top of my head.
I think when she turned vampire she realized that she dose not need to change Klaus. He already knows all those things. He was perfect the way he was.
Now that Cami is gone, there is no one to assert him of his good thoughts. That will be a challenge for him. Having another person backing up your thoughts can be great affirmation.
Thoughts?
------Choose your relationships wisely. It's better to be alone than to be in bad company------