From Atlantic—the main point of the article:
Because the truth is, if you want to get paid as a writer, finding your own voice can be a distraction—even a hindrance. The bulk of writing opportunities that will actually provide you with a living wage are work-for-hire—writing textbook entries, or exam questions, or website content boilerplate. And when you’re doing work-for-hire, no one cares about your voice. Or rather, they do care, in that they actively don’t want anything to do with it. The point of work-for-hire is to make your voice disappear into the house style.