That's an interesting point. I think style and versatility aren't, or at least don't have to be, all that related. Style can mean lots of things; from something quite abstract like your style of story telling, through to your style of character and finally your actual writing style (ie what words you use). I certainly have a strong style of story that I like to tell; built around good people doing bad things; and I like a certain style of characters; with weird, unique perspectives and with lots of internal conflicts; but I've told very different stories with them. I've written one book about politics, one set in a cult and one that's a highschool drama; a pretty wide breadth of material but all of them definitely have my dark little fingerprints on them. You can tell within a chapter that the world inside is somewhere dark and sad and very 'me'. So does that make me versatile or not? I have no idea. There's threads that tie my books together but they are very thematic. I know I couldn't just abandon all that weirdness and still think I've done a good job; even trying to write without it I end up taking stuff in a dark, introspective direction, creating internal strife rather than writing about the bigger plot. But I think I write all my characters well with unique voices and approach the world in unique ways and I think I write them well. I certainly have a strong sense of style and mood (I like to call it 'Emotional Whiplash') but I explore all kinds of different material with it. Whether that makes me versatile particularly is up to the reader I suppose.
I've written three books and dabbled in a few other genres with short stories. Though my first book was a sort-of fantasy it doesn't fall into what I'd call traditional fantasy. It was essentially a romance guided by a supernatural occurrence. I enjoyed writing the characters and their interactions but the otherwordly stuff caused me to struggle. The other two books are character-driven thrillers. The action that takes place within is the most difficult for me to write. It has to be logical, believable while also being dangerous and exciting to the reader. Aside from worrying about logic in my plot I find these easiest to write. I've found it easy to write romance, action, 'dark' or gritty stuff, and light humor. My thrillers have sex scenes in them, some of which are probably contenders for erotica but I find them difficult to write. Making them sexy without being tasteless is tough. I know I could write regular erotica (I've done it as a practice exercise) but I don't enjoy it. Sci-Fi I can't write; I just don't have that kind of imagination. Ditto vampires and werewolves. Couldn't do Harry Potter type stuff or Hobbitts. Those genres don't interest me. I've done some horror short stories that aren't too bad but I'm not drawn to them. I'm happiest writing about normal people in modern times being challenged by things seemingly insurmountable that they figure out how to overcome on their own. Better if I can keep the reader guessing while I'm doing it. The rest of it is incidental.