The short version is that anyone who wants to have a reliable fire source with them at all times can do so, and for ridiculously cheap.
I have nearly a dozen ferrocerium rods of various sizes ("Firesteels") stashed in various places, and nearly always have one with me. I find them more reliable than any other technique/tool that is handy enough to carry around everywhere. I particularly like using an old tylenol/aspirin bottle with a small firesteel & striker inside, with cotton balls filling in the empty space. A little pill-sized ziploc contains a bit of vaseline, in case I can't make a feather stick for some reason (A good feather stick and a cotton ball should take you from spark to small cooking fire...).