Why is it so hard to get a fantasy novel published?

Fantasy is a genre wherein most books are produced by a very few (big) publishing houses in the UK and USA. These are the houses that can afford to take the risk on large print runs because they have many other titles too. They also have significant advantages in economies of scale (cheap distribution, discounted printing, efficient representation to the stores). They produce a few fantasy titles (bad luck, authors) in big volume. Big volume is necessary for most kinds of book printing, but f...