In a time and age in which we prefer easy solutions to complex problems, we do not wish to learn from a complex past. Finally, and perhaps most crucially, in a time and age in which what is new and young is held to be the wisest, we reject the experience of older members of our society. To ignore the full weight and measure of human history, and the historical process which helped shape us into what we are, is an act of cultural suicide. Still, it's important to keep in mind that those who write history, study it, try to reveal it, are themselves the products of history. That is to say, any history we claim as completely objective ignores the fact that it itself has been shaped by the historical process.
History is never simple, finite, without contradiction, or even perfectly knowable.
It is never completely objective. It is constantly changing. Those who write historical fiction are equally products of history. But the writer of historical fiction has a different task than the historian. Historical fiction uses the past so as to better understand the present.