This question comes back to a debate I see come out time and time again in the writing community. Should you write with a target audience in mind? Some writers say it’s essential. Others have said it’s a form of pandering, among other things. There really isn’t a wrong answer here. I am a big believer in Stephen King’s “ideal reader” strategy.
In On Writing, Stephen King approaches the issue of target audiences with what I think is a really practical solution. Don’t write it for just anyone, but one person. This idea captures a “target audience” in some ways, but in others, it leaves it much more open in others. This way you’re not sitting around thinking, what do teenagers today want to read? and more along the lines of what would I write for my little sister? You’re not pandering towards some vague, imagined person, but creating something for one person who you know and care about.
An example: I could write a story for my cousin that is about girls who don’t let a guy destroy their friendship. While that story might be important for my cousin, on that premise alone, it might not be the first book on the shelf my brother would decide to read. It wasn’t written for him exactly. With that said, he could still enjoy it. My cousin loves sword-fights, action-packed plot lines, and espionage. So, what if these two best friends were spies? What is the guy that came between them was their target? What if one girl fell in love and the other feared she would reveal their mission? My brother might decide to read that book. He likes spy-dramas too. It might not have been especially crafted with him in mind, but there’s no reason he wouldn’t also enjoy it.
More than a few genres tend to market more heavily towards women. Some genres almost exclusively market towards women. Stats out there show that, in general, women tend read more fiction than men do. Not every book is going to appeal to every audience and that’s not necessarily a problem. For instance, The Catcher in the Rye by J.D. Salinger tends to be a controversial book when you ask for reactions. It’s a book that taps into teen angst in a way that few are able to. As a teen, I found it incredibly relatable. Holden and I had more than a few things in common. With that said, there’s no shortage of readers who don’t relate with Holden Caulfield (or simply don’t want to). He’s not the most likable character. But for the readers who struggling with any of the number of things Holden is going through, this book is worth the read.
The last thing I want to note is that the gender of your protagonist is not necessarily going to deter readers. Girls read Harry Potter. Boys read The Hunger Games. And sure, in these examples, there are secondary characters of the opposite sex, but there doesn’t need to be for a book to be beloved. Growing up, one of my favorites was Lord of the Flies. No girls in that book. While it may matter to a few readers, ultimately, a good story is a good story.