Money is actually a pretty good motivation for a lot of people who contribute to FOSS. It's not all about artist mentality.
75% of Linux is now written by paid developers. (http://apcmag.com/linux-now-75-corporate.htm) Many other large FOSS projects also have a varying number of paid developers. Since a lot of companies who employ such developers (e.g. Red Hat, Novell, Google) rely on FOSS for their business-critical applications, they have a good motivation to make sure that the software they use perform well. Of course there's also hobbyists, volunteers, and people like RMS who believe they have a profound obligation to promote FOSS.
there's also hobbyists, volunteers, and people like RMS who believe they have a profound obligation to promote FOSS.
I wouldn't consider that these two as completely distinct sets of people. Most of the paid Linux developers I know of (not necessarily a representative sample, but a fair few) started doing it as a hobby, and still do similar things as a hobby in their spare time. They're being paid to do it now because they were very good at it, and a particular company wants some say in exactly how it's done.
A former co-worker of mine put it pretty well: "Quiet! As long as they don't know that we'd do this stuff anyhow for free, they'll keep paying us to do it!"
75% of Linux is now written by paid developers. (http://apcmag.com/linux-now-75-corporate.htm) Many other large FOSS projects also have a varying number of paid developers. Since a lot of companies who employ such developers (e.g. Red Hat, Novell, Google) rely on FOSS for their business-critical applications, they have a good motivation to make sure that the software they use perform well. Of course there's also hobbyists, volunteers, and people like RMS who believe they have a profound obligation to promote FOSS.