Just weeks before his assassination, President John F. Kennedy gave a speech at Amherst College in which he talked eloquently about the role of the artist in society:

If art is to nourish the roots of our culture, society must set the artist free to follow his vision wherever it takes him. We must never forget that art is not a form of propaganda; it is a form of truth. And as Mr. MacLeish once remarked of poets, there is nothing worse for our trade than to be in style…

So be free and let your writing take you where it wants to go, whether you think it’ll sell or not. As Kennedy said elsewhere in the speech, that’s your duty as an artist. Society depends on you.