Lots of interesting comments, but just to address one of the original poster's specific queries, I almost always carry an axe, (actually a hatchet with a hammer poll), for one reason: A hammer is very often necessary for setting up a tarp in the hard Aussie soil and so you might as well have one with a blade on the other side. Yes, you could try using a baton or rocks, etc but for the sake of avoiding bruised fingers it's easier to take a proper tool.
And the real reason - it's fun to play with.