I see a lot of authors in their query letters talk about how their books reach out to a wide variety of people. Mostly, I see this as they try to argue that their book crosses so many different genre lines. While cross genre writing does work, attempting to make your book reach everyone is not often going to work.
Think of it this way. People who read historical fiction like this genre because of the nuances it provides. People who read sci-fi like it for the same reason. In many cases, readers frequently do not shift between those genres. As you write your stories, trying to blend those genres might often work against you.
Along the same lines, if you are thinking that your book becomes more marketable if you can meet so many different populations, it might sound good, but again, realize that your story really does have a target audience and focusing in on that is going to be much more effective.
As an agent, I love to see an author know exactly what their story is and who it targets. This really does demonstrate your knowledge of the business. When I see someone someone throwing everything out there, this really tends to demonstrate someone who is just hoping something "sticks." In many ways this is like those authors who send out a mass email to every agent or editor.
Don't try to reach out to everyone. Focus, focus, focus! You'll be much happier.