First, having several methods of firestarting makes sense as a backup. Matches and lighters can get lost, break, get wet, etc. MFS and other strickers are virtually impervious to the weather and will work when the matches and butane run out.

Second, I've been surprised on how easy it is to start a fire with a MFS and half a hacksaw blade. On campouts, I have them on a keychain at my side and it's almost easier to strike a sparks on demand than it is to fumble around with matches. Plus I get a sense of confidence when I do so that doesn't come with striking a match. <img src="images/graemlins/wink.gif" alt="" />