I have been told a few times to try and write something that I think people want to read. For example, gothic romance or whatever you call books where sparkly vampires chase star crossed loves who seem to perpetually hate something about their life.
I love so many genres, but there are only a few that call to me.
In my opinion, your genre pretty much picks you. That's not to say you can't step outside the boundaries if inspiration strikes, but I would resist the urge to try and force it.
I like Sci-fi, fantasy, horror, westerns, steampunk, superheroes and historical fiction. I can't imagine, right now, writing much else. I have considered, a few times, writing a football fiction story using all imaginary players, a different league, etc. Pretty much "Blitz: The League" in a fiction format...or "Playmakers" in written form. "Playing for Pizza" was good. So was "Ruffians."
I would write short stories each season so readers could see the league change over time. Players would retire, teams would rebuild, there would be scandals, suspensions and career ending injuries...but I digress.
A bit more about letting your genre choose you. I think you write what you feel led to write. Anything else will seem inauthentic, and rightfully so.
Oh...on the football idea, I haven't done anything with it yet. If you like it, feel free to run with it.