The quote above is just another variation of If you're going to do it, do it right. As writers, we put a lot of time and effort into writing a story, essay, article, poem or a novel. Some have even said we do it with blood, sweat and tears.
By sending our work to an editor in hopes it will someday be published, we take a big chance. If our words are seen in print by myriad readers, we've put our soul on display. We're telling the world to listen to our words. This is who I am. If you write dark, negative pieces, readers will get a glimpse of your outlook on life. If you're always upbeat in your writing, chances are that's the personality you have.
But it doesn't matter. There's a place in the world for both kinds of writers. There's a place for writers who choose one genre over another. Whether it is science fiction, horror, paranormal, romance, mystery, religious or humor doesn't amtter a twit. You should write whatever makes you comfortable. You should write about things that you know and understand.
The one thing that does matter is that you do it well. Be a good one as the quote above tells us. Strive for excellence. If you do a half-hearted job in your writing, it will be very apparent to the world. You might even get it by an editor and see your work in print, but readers figure out pretty fast that it is not your very best work.
More than once, I've read reviews that flatly declare that the book was not up to the writer's usual standards. If I were the writer who had been criticized, I think I'd squirm a bit (after I ranted for a few minutes in anger) but then I hope I'd ask myself if I'd done the best job on that book that I could.
This is reminding me of something my mother often told me when I was growing up. She'd show me how to do some household task, then she'd leave me to try ti with a warning --"Do it right, or you'll have to do it over again." I heard it often enough that it's stayed with me through these many decades til now.
Strive for excellence. Whatever you are, be a good one. Methinks they are good words to live by in our writing world and the rest of our lives, too.