Sorry, is it not you who speculated this?
"Italians generally don't like to work any harder than they have to "
I can speculate that their axes are like this because mediterranean climate creates a specific environment in which humans have to work. When the heat is taking the toll maybe you don't go for 3' diameter tree to cut down, but you go for "close to your needs" size of tree. When your houses are 99% masonry, you don't need huge quantities of wood. You need a tool capable to fell a decent size tree and do fine tuning for rafters, windows, doors, furniture etc. You will develop an ax good for these parameters. It has nothing to do with their work ethic, speeding or marathoning.