Authors Moshin Hamid and Zoe Heller attack this question from either end, and I think both of their points are, well...poignant.
In their article "Are We Too Concerned That Characters Be 'Likable'?", Hamid and Heller look at what makes a book, based on its characters, likable. Hamid states, on the one hand, that finding 'nonlikability' as an unacceptable flaw is in itself incorrect.
"I confess" he states, "I read fiction to fall in love. And in fiction, as in life, characters don’t have to be likable to be lovable."This is an indelible truth that I think many readers miss. Yes, we read to escape, or to learn, or to be entertained. I for one don't like graphic or scary movies (or books, for that matter) because I don't find them entertaining. They aren't likable. But there are some instances where I can appreciate a certain style or character that I maybe don't like because I can see the artistry behind it. In my own experience, this happened the most clearly with The Hunger Games. Katniss Everdeen starts out the book as a 'likable' character. In fact, you love her. You want her to win. You want her to survive and be the hero and save the districts.
By the end of the second and throughout the third book, I really didn't like Katniss. She was, in the end, emotionally and psychologically harmed and twisted by the events that had taken place to her. She wasn't perfect. She didn't have all the answers. She was downright annoying at times. But who wouldn't be, faced with what she had to face? I was flabbergasted, and in fact I was impressed with Suzanne Collins for not only tearing down the 'heroism' of her heroine but also taking the honest, true-to-life approach that so many fiction writers can miss. It's like losing the forest for the trees. If you're writing a fantasy or a fiction, you want it to be believable, real. You want your readers to step into your world and see it as possible.
And if it isn't realistic, then they aren't going to find it easy to believe. Done.
On the other hand, Zoe Heller attacks the idea of making 'likeability' an option rather than something to seriously consider. She states that:
"I grew a little uneasy, though, when in subsequent Internet discussions a consensus seemed to emerge that caring at all about “likability” was an embarrassing solecism, committed only by low-rent writers and hopelessly naïve readers. This struck me — and strikes me still — as faux-highbrow nonsense."Liking a book or a character does not mean that they aren't deep. You don't need sardonic, cynical, moody characters all the time. You don't always need a commentary on the faults of the world or of humanity, life, the universe, and everything. And sometimes you'll lose your readers if you don't cater to their desires-- a desire to learn something, to escape, or to be entertained. If all you do is tick them off or make them feel bad about themselves and life in general, you're not going to get very far. To Heller the idea of whether likability is a successful factor or not is very similar to Hamid's idea about 'realism'. Heller declares that the importance of a character is whether or not they're "alive". When your character breathes and has a beating heart and sweats and bleeds, they can be likable even if they're deplorable. You know those villains we 'love to hate'? They're alive.
Heller sums up this argument by using Shakespeare as an example of likability:
"It’s not necessary to “like” Hamlet, but if we’re so repelled by his treatment of that sweet girl, Ophelia, that we withdraw all sympathetic interest in his dilemmas, then the play is unlikely to mean much to us."Ok. That's pretty clear.
So the issue of "likability" is more a point of whether your characters, your book, is alive or not. If it's too perfect, it doesn't seem real. If it's too imperfect, no one will like it (or your reader base in either case will be so small as to be pretty meaningless anyway. Then again, John Updike is considered a classic American author. Well, there's no accounting for taste.)
Make your characters real. Make them live. And if that means making them do horrible things sometimes, do it. If it means making a hero who never gives up, do it. But don't tie your flag to either one side or the other.
In everything, a healthy dose of moderation...