Why don't American publishers ever take a chance?

Almost impossible to believe that books like those of Hans Keilson have been published in the U.S. - why would an American publisher even a 100-page meditative, serious novel set during World War II, but without battles, concentration camps, great love stories, heroism, or in fact any of the usual elements that might conceivably turn into sales or film rights. There's no way Keilson's work would fit into any kind of marketing plan. Let's see, we gonna send a 100-year old Dutch author out on a speaking tour? I doubt it. But somehow in one of those rare twists of fate talent has been recognized and virtue rewarded and FSG has published two Keilson novels, bringing at least some attention to a writer who I believe was virtually unknown to Americans till last year. Started "Comedy in a Minor Key" last night and haven't read deeply enough to say much about it - it tells of a couple sheltering a man (Jewish, presumably) in their attic in a quiet Dutch (I think) neighborhood, and the strange relation and dependency developing among them and the odd fear and ambivalence they all feel as Allied air forces fly over and begin attacks, wondering what will be their fate, uncertain who in the neighborhood might still betray them and who else for that matter might also be harboring Jews in the attic. This book, from 1947, so unlike anything published today, I'm glad it's been rescued from oblivion and that maybe it will show American agents, editors, and publishers that it's OK to take a chance now and then on writing that may be different, that bears the stamp of history and authenticity and suffering.