I would say:no. There are many writers who would write in a multitude of genres and publish in it. As not all can be cookie cutted into one genre or fitted. There are times when another genre suits it best. And it’s always good to branch out. Various genres reach you to focus on different things, and helps your writing in the long run.
Of course, I’m not asking you to write a book in every genre. Experiment a little and decide. I write fantasy with historical fiction mostly due to my love of lush, exotic settings and that I’m willing to spend the time to research it heavily. As well as find various places to set it in or inspire it off. And that I love nuanced characters, and characters who have little choice but do what they do.
I don’t really have any fondness of science fiction, I really don’t. Since getting an idea can be hard work, and with my knowledge of science I still have no idea. Because before I actually step heavily into a work and begin the first draft, I would plan out the concept and the world. Thanks to my experience with planning high fantasy concepts, which needed to be solid and having some sense to develop the world.
As for what I learned about stepping into historical fiction is the importance of research as I’m also a history purist and would want everything to be as accurate as possible. Which means having to take my research and making sure it is accurate. That ensured my endless focus in finding various sites to confirm mgmy findings, be it in one language or another.
And that from stepping into various genres is that I have learned a great deal about the style of them, and how it works there. Every genre has a different focus, though the other parts cannot be neglected. Such as a mystery novel, when the focus is on the plot but the characters cannot be flat otherwise no one would find themselves invested in the book. For romance it’s the relationship and the hardships, but at the same time it should have a plot that makes some sense.
What about you? What do you think? I’m quite the fantasy based writer, since I have so many high fantasy ideas. But I branched out for some ideas, as they couldn’t be used for that one genre.