In reference to Aglaranna, her falling for Tomas was actually more of what he had become than who he was... The race of people who he was sort-of turning into were their masters, and it was kind of built into Aglaranna to be submissive to him, so it's not just the hero factor there.
Sorry, those are my favorite fantasy novels of all time.
I think to make a viable world, there has to be some degree of feminism in the story. Feminism, however, is different than including a female character. Any character can be empathized with if they include elements of both sexes. Sometimes, that has to be done forcefully through an omniscient narrator, however. Men are generally less openly emotional than women, but if you make a male charater's emotions more accessable through that omniscient narrator, you make him accessible to both men and women, because men know that while they don't show emotions as much, they still have them, and describing those emotions through the omniscient narration allows a female reader to relate to him. Female characters who are emotive in a story seem natural to both men and women. Of course, men and women have different emotional responses to different situations, but done well it won't make too much of a difference.
So, in conclusion, female characters may not be necessary, but a general understanding of humanity is essential.
Just call me Captain Obvious.