Characters in a book don’t have to be likeable. In fact, some characters/protagonists are deliberately written to be absolutely repulsive. What is important is that you have to understand where they’re coming from, what their values are. They have to be believable.
One of my favourite books is Baggage by Emily Barr. One of the characters is a journalist named Lawrence Golchin. He’s not the main character, but he is a POV character; in fact, come to think of it, he’s actually the book’s antagonist. When we first meet him, he only talks about two things: his career and himself, which makes it pretty obvious what his values are. Larry steals contacts, sabotages office property, cheats on his girlfriend and says it’s all right to further his career at the expense of others. He is desperate to get his own big scoop.
When his girlfriend Sophie comes back from holiday, she tells him a very strange story: her best friend, who supposedly committed suicide ten years ago, is alive and living in Australia. Daisy Fraser was waiting to go on trial over the deaths of four people; now, she is living under a different name and has a husband and a son (neither of them know who she really is or what she’s done). She’s also pregnant, but Larry and Sophie don’t know this at the time.
It takes Larry about ten seconds to realise this is his big chance – if he can prove it’s actually Daisy. He takes Sophie back to Australia to track Daisy down, promising that he won’t tell anyone and having every intention of telling the world. He’s manipulative, selfish and doesn’t care who he hurts as long as he gets his story.
Larry is relentless in pursuing Daisy. Even when other journalists come on the scene (including the one he cheated on Sophie with), he is determined to get an interview with her. In fact, he thinks she owes it to him. He even decides to bring Daisy’s young son into it. Larry’s big break is actually coming at a very high price. Not only does he lose Sophie, he loses the respect his family had for him (not that they had much respect for him in the first place) and he is told at least twice that the locals don’t like what he’s doing, don’t like him and that he shouldn’t stay in the location for too long. But in his mind, it’s worth it.
Then Larry starts sleeping with a photographer assigned to the case. The photographer is a genuinely good person and even invites Larry to come back with him to Sydney to pursue a proper relationship. This is Larry’s chance to turn back from the path he’s on. He could leave Daisy and her family alone and begin a new life.
Larry doesn’t take that chance. He stays in the area even after all the other journalists and photographers have left. He’s not going to leave Daisy alone until he gets what he’s after. Unfortunately, Daisy’s husband and in-laws figure this out as well and what happens next is pretty much inevitable.
Did I like Larry? No, absolutely not. But I did know where he was coming from. His decisions, nasty as they were, were true to his values. He was believable as a character.