So, does demanding diverse books mean there's a responsibility to write them?
At first, I thought no. I'm not going to force diversity into my stories. I want it to happen naturally. But after reading The Authorteers answers, more specifically what Jessica said about being Polish and Marie said about nut allergies, I rethought my answer.
I have one story I'm working on where my main character is a blond white girl, but her diversity is in her heritage. Her father's side came from Scandinavia, so her last name reflects that. Things like that are a small shout out to the different cultures that make up the world. Another story I was able to do something I've been wanting to for a long time. Have a character with a craniofacial disorder. It's not even vital to the story, but I gave her that trait because it's important for people who have them to see those characters in books. (It's also personal for me because of my nephew.) I made sure to weave it in naturally.
Diversity is MORE than being LGBT or having a different color skin. It's a million different things. They don't have to be in your face either. It can be subtle, like searching for a certain ethnicity when looking for cover models, or choosing a name that is common in another part of the world, or giving your character a scar from a surgery she had when she was an infant to correct a cleft lip. (These are all things I've done BTW.)
I think Eliza at The Authorteers said it best:
I don't think we're inherently responsible for writing diverse books, but I do think we're responsible for telling the stories in our hearts--and those will naturally be diverse tales, as we're all different.