Authors don't write for money, they usually have a second job...if I was out of work, I would start writing just for something to do until I found another job, or if I had the time in the evenings I would write.
Authors make money, but most don't make enough money to keep them going, especially not a regular salary. There are exceptions, such as J.K. Rowling, but if you have ever heard of Meg Cabot - she's written a lot of popular books for teenage girls and she still earns well under the average salary. She writes because she loves it, and that's why I write. Chances are, I will never get published but it won't stop me from having fun.