Right - Linux, OpenOffice, Unix, C, even Perl, were all things that someone built in spite of there already being something similar out there. And the people did many of these things on their own, for the love of the work and not for the money. Come to think of it, even Einstein wrote his three major papers (including the special theory of relativity) in his spare time.
In my experience, most bosses are too caught up in the so-called bottom line, that they overlook how much valuable stuff is done by people on their own. They usually can't see beyond the next financial report. But that's OK. Many of us do for fun what others wouldn't do for money. Getting paid would kind of take the fun out of it, IMNSHO.