Ireth
Myth Weaver
Realistically speaking, most writers write about the kind of romances they personally find attractive. Since most people are born heterosexual, of course most writers will write heterosexual romances. That includes yours truly. That doesn't mean a straight writer can't or shouldn't write a gay romance if they so desire, but odds are they won't enjoy it as much as a gay writer would (assuming the gay couple is the same sex as the writer in question of course).
Exactly. I started out Low Road with a deliberate choice to make the hero asexual, or at least not interested in romance. I wanted to add a heterosexual romance between the MC's sister and his best friend, but that didn't work out. Instead, the best friend wound up falling for the hero. I didn't even consider trying to force a hetero romance back onto the characters, but took what I had and ran with it. And I think the story is (or will be, as it's not yet finished) better for it. For the record, I'm a female, and the gay couple in question are male. I also have gay and bi characters of both genders in other works of fiction.