I'm ten years in the writing game now. Admittedly, I entered my MFA with a goal: Be Famous. The naivete sustained me and I have no regrets. I plunged and emerged a better writer.
Although initially wanting in the fiction program, I (confession) applied in nonfiction because the then-director told it was less competitive. I figured once I was there I could do both, which—with finagling and taking two workshops for three out of four semesters—I did. My nonfiction was also more developed at the time (I'd worked in journalism and had publications). I knew that my NF was the stronger writing sample, and looking back at the fiction I had then, chances of my acceptance against all these BFAs with at least one polished story was slim.
One aspect I have discovered I don't care for, as I extend my stay in the academic writing world with a PhD, is genre pidgeonholing. This was why I dropped out of a Lit MA fifteen years ago. I didn't want to spend the rest of my life writing critical articles on Jungian analysis and feminist criticism of Eudora Welty for ten other people in my field. Again, I applied in nonfiction because I had a developed book project. I knew that genre was my strongest writing sample/application. So, my "label" is nonfiction writer.
To be clear, I'm not writing nonfiction to get in programs. I love nonfiction. I have a nonfiction book coming out, and believe me, if I didn't love writing about Laura Ingalls Wilder and researching the 19th century and writing memoir, I could never have finished.
But I have missed writing fiction. I recently entered and won a fiction writing contest for the Ohio Lit Fest, and people came up to me, wondering if the were going to "lose" me, which makes no sense. Maybe, for my academic job, a particular focus is best. Although Montana just hired David Gates, for fiction/nonfiction. So maybe not.
On the other hand, sometimes it's admittedly annoying when people publish in all three genres. Like, make up your mind already. And often, you can tell when an author has a particular strength. Well-known authors, especially, can get their perhaps-not-best-material published in a lit mag because of their name.
Oh well, I just published a poem anyway. What? Although I might like my bio better than the actual poem.