Really? That averages out to about $10 an hour, I suppose, if you're a fast writer, don't need to do research, and have no expenses. So if I wrote 8 hours a day, 5 days a week, just like a "real" job, it would take me about 2 1/2 weeks to write a book. I could write almost 2 books a month, so I'd make about $1600 a month.
But...that's before taxes, so figure that I'm going to pay 15% social security and 10% income tax on that income, I have to pay for my own health insurance, dental insurance, and any fees for advertising, web hosting, etc. out of that too. Now I'm down to about $600 a month net. Can you live on that? Neither can most authors. And writing doesn't work that way (unless you're Nora Roberts, who I've heard CAN write 8 hours a day, every day.) It takes time to come up with an idea, a title, characters, names, a cover image (those can take a full day of searching sometimes.) It takes even more time to rewrite, edit, & re-edit because God forbid there should be a typo in the manuscript. If there is, some readers will murder you in the reviews. Then there's the full day it takes to write front and back matter, format, and upload the books. And after that you have to promote it or it will languish.
Most authors need to make at least $10,000 per book to make a living wage. That's figuring on 4-5 books per year. But what if you write slowly, or you're the kind of writer who wants every word to be perfect, every scene and sequel and transition to flow and have meaning? Then you're not going to write 8,000 words a day every single day without needing editing time. And you're not going to live well on $10,000 per book. You're going to need to make $20,000, $25,000 or more per book to make a decent wage from your writing.
If your book sells for $0.99 on Amazon or B&N, that means you have to sell 60,000 to 100,000 copies to earn what you need to on that book. Not many authors sell 5,000 copies of their books per month. And yet if you price it higher, say at $2.99 each, you're going to sell way fewer copies than you would at $0.99. It would take selling 10,000 to 25,000 copies of each book to earn a living. But readers begin to balk at paying $2.99 per book. They think, since they're e-copies, they should be cheaper. But the price isn't about the cost to sell, but about value.
We think nothing of plopping down $8.99 for a Nora Roberts book. That's because we perceive her value as worth that amount of money. But would you spend that much on an unknown author? Probably not. But that unknown author may be just as good, and just as worthy, as Nora. You just won't know it until you read it.
At some point, authors have to make a living at what they love--writing--or they're going to have to return to the regular workforce to pay the bills. And then they're too tired to write, or too discouraged, or too stressed. And you will miss out on some of the best stories yet to be written.