Open Source is not a business model
Which is not to say you can’t make money out of it
A common theme nowadays in the open source developers’ circles is that you can’t live writing open source. There are sad accounts of people abandoning their (popular) open source libraries, frameworks or programs, because they suck too much of author’s time and with little or no financial gain. Others try their luck at Kickstarter or Indiegogo campaigns for funding a few milestones of their project, or set up a donation system via Gratipay, Flattr or Patreon.
This conflates several different approaches to making money off of open source, each of which requires a different way of thinking about how the money is related to the work.