Lately, I've been pondering moral issues.
As a historian I frequently come across difficult topics that can be tough to handle professionally. I wrote my thesis on the Middle East conflict. I now teach about World War One and Two. Constantly, I run into issues that are difficult - if not impossible - to handle without passing some kind of judgment. The dropping of the atomic bombs over Japan, for instance. So many factors to consider, making it a very complex moral question.
In my research and teaching, however, the solution is fairly simple. As a historian, you are not supposed to pass judgment. Personal opinions are less interesting than professional explanations and analysis of the issues of the past. Whether something is "right" or "wrong" isn't relevant. It may not always be easy to avoid having opinions, and it may not be easy to avoid voicing them, but at least it is a yardstick we can keep to.
This goes for academic writing, but not so much in other genres.
In fiction writing you will also frequently run into moral issues, and you have much less restraints in terms of what you can and cannot do. You don't have to keep to academic standards or give justice to any sources, unless you chose to, of course. You are free to portray any issue which ever way you want - as long as you are prepared to face the concequences.
Because - even if we as fiction writers have no formal obligation to avoid passing judgment or meddling with complex moral themes, we may still face repercussions. People will still have opinions about the subjects you address, and they will not hesitate to pass judgment on you as the author if they disagree with your position.
Nabokov's Lolita seems an apt example. In this case it is, perhaps, his lack of passing judgment that has caused the controversy - the narrator, a middle-aged man, attempts to justify his own sexual relationship with a twelve-year-old girl. Nabokov found his novel first rejected; and then after publishing, banned many places. Eventually, however, it has come to be considered a classic and a must-read.
Moral issues engage us. This is why it is difficult to convince students that they need to strip their academic papers from them. And this is why controversial books that deal with moral issues frequently are prainsed and banned, often simultaneously. As fiction writers, then, we should perhaps seek to deal with these issues rather than avoid them?