Should making money be the incentive to write?

Dear Literary Ladies,
I write and write, sometimes getting compensated for my efforts, but often not. I just feel this incredible urge to keep putting words to paper, whether I get paid or not. Am I being foolish or naive? Should I try to do the kind of writing that might bring in a few bucks?

As for me, when money comes, I say, “So much the better,” without excitement, and if it does not come, I say, “So much the worse,” without any chagrin. Money not being the aim, ought not to be the preoccupation. It is, moreover, not the real proof of success, since so many vapid or poor things make money.

— George Sand, from a letter to Gustave Flaubert,
ca. 1868