Open source software puts the lie to the theory that everything must be driven by the profit motive.
Free software _is_ driven by a profit motive. One form of profit is in having a better piece of software to use. Another potential profit is in intellectual fame and glory. And finally most fulltime FOSS developers are employed by companies who market distributions. Just because FOSS doesn't fit into your traditional view of how capitalism operates doesn't mean the fundamental economic principles of incentive and reward don't apply.