Who Doesn't Use Source Control?

VegeBrain asks: "I was reading the description for for a new book, Pragmatic Version Control using CVS and was shocked to read that 'Half of all project teams in the U.S. don't use any version control at all...' Is this true? If so, why? I can't imagine being without one so I'm wondering why anybody would avoid using one, especially now when so many are available for free. Am I missing something here and there really are reasons to not use a VCS?"