When considering the overall systems and wiring methods used in North America vs. Europe (rather than just 120 vs. 240V with everything else being equal) I think in both cases it comes down to the quality of the installation, it's proper planning and use of the correct materials.

I know some people from this side of the pond who look at American wiring with apparent horror, often citing things such as no shutters, unswitched outlets, non-sleeved plug pins, and so on.

I think the average American would be equally shocked (no pun intended! [Linked Image]) at some of the methods used here, e.g. the casual way in which service entrance conductors are strung through roof spaces with no conduit, the cramped space in our boxes, etc.