Lyda wrote on this topic a few days ago. I wrote my own post for my blog. Here it is:
For most writers, writing is a lot of hard work, often while holding a day job to pay the rent; and the return is dubious. Even most published writers don't make a living. There is always the fear, if you are midlist, that you will become unpublishable. The publishers aren't making enough money from your books. You aren't breaking out. You will never (it seems) become a best seller. The publishers will drop you.
If you are published by independent presses, then it's almost certain that you won't make a living.
I suspect most people go into writing in the hopes of becoming famous and financially comfortable, maybe even a little bit rich. At least doing well enough to quit the day job. So, what do you do when you realize it isn't happening?
I think you think about why you write.
There is love of craft. There is love of telling stories. There is the pleasure of whatever praise you get. Sometimes, you touch people. They write and say your work meant something to them, made them happy, helped them through a rough time.
For me, writing is a way to cope with a world that often seems way too dark. It's full of unmaking -- governments that don't work, infrastructure that is crumbling, wars that destroy nations, neglect that destroys individuals. So I make something. I try to make it funny and hopeful.
In my community, the SFF community, being a writer counts for something, which is another reason to write. You get to be on panels. You get free memberships to cons. People even sometimes ask for autographs.