But projects like KDE have hundreds of active developers, with hundreds more who have submitted bug fixes and new features. Some free software projects have thousands of people actively working on them. Free software is not bound by the dictates of a company's marketing department. There is little pressure on free software developers to rush things through, so it is very rarely of slipshod quality. Free software developers work on their projects because they want to, and not because their boss tells them to.
Free software is one of the few places left where old fashioned craftsmanship still abounds.
However, you can't make very much money selling just the software. Put too high a price on it and you customers will simply download it instead. However, a lot of people like the convenience of having a shrink-wrapped box with a CD and a manual. And some companies won't use downloaded software, but are more than willing to pay for exactly the same thing through more traditional channels. You can also charge for support.