I enjoy writing for money, it’s everything Noah Berlatsky describes in his October 9, 2013 Salon article, "Why Unsuccessful Writers Give the Best Advice". In it, he contrasts himself with Ta-Nehisi Coates, a celebrated writer who'd recently been profiled in The Atlantic, quoted as saying that in his writing Coates never achieved "that perfect thing that was in my head, so I always consider the entire process about failure."
Aside from those times I write to be paid, I am far more often compelled—best word to describe it—to write great quantities of made-up stuff that, having a life of its own, strongly resists shaping itself for any other audience but me. It’s embarrassing, but enormously satisfying. I certainly rewrite my creations as necessary, but I’m not preoccupied with perfection, really, only clarity. Nor even in my compulsion do I experience the existential struggle Coates describes. I just need to write. It would be nice to be paid, but fulfilling my needs is welcome compensation.
I will say that if I only wrote for money, I could say I write because it’s expedient to do so. The writing for myself, out of compulsion, is what makes me a writer.