There seem to be an infinite number of things for which agents and publishers are searching. There are an infinite number of pitfalls and ways not to fit into their prescribed box. But the issue that no one addresses is this – if you try to give them what they want, it very likely won’t be any good. Alternatively, if you make something good, most of the time it won’t be what they want. So the issue becomes, do I do something I love or something that I’m told will sell?
There is no universal right or wrong answer. But what I would wonder about the agent or publisher is, if they are so sure about what it is they are looking for, then why aren’t they writing it? Why not cut out the middle-man, you, and create the work themselves?
The only conclusion is that they can’t. For whatever reason, they are incapable of producing the work, or, in spite of their specific criteria, they don’t actually know what it is they want.
So, although I continue to grapple with this issue even as I write about it, what I would tell anyone, myself included, is not to worry about what they want. Do the best work you can and make sure it’s something you love. If you’re just going through the motions in the hope of pleasing someone else, you may as well find an easier job.