Lionel Shriver

We have explicit expectations of ourselves in specific situations–beyond expectations; they are requirements. Some of these are small: If we are given a surprise party, we will be delighted. Others are sizable: if a parent dies, we will be grief-stricken. But perhaps in tandem with these expectations is the private fear that we will fail convention in the crunch. That we will receive the fateful phone call and our mother is dead and we feel nothing. I wonder if this quiet, unutterable little fear is even keener than the fear of the bad news itself: that we will discover ourselves to be monstrous.
—  Lionel Shriver, We Need to Talk About Kevin
I’m less concerned that you love my characters than that you recognise them. Human beings have rough edges. Authors who write exclusively about ethical, admirable, likeable characters are not writing about real people.
— 

Excellent piece by Lionel Shriver in defense of unlikable characters.

We Need To Talk About Kevin author Lionel Shriver: Why Literature Requires Unlikable Characters - Slate Magazine