It deals with how electrical power delivery was initially setup and deployed. Europe uses 50Hz power phase while North America uses 60Hz and technology evolved to keep in sync with it and you can't just replace the entire power grid to go up to 60 like you want.
Not sure, but read it has to do with the electricity.
Ours in the USA is 60 Hz and in Europe, it is 50 Hz
Us, Canada and Japan are 30/60 fps because of NTSC.
The rest of the world uses PAL, which is 25 or 50fps.
Different protocols. Europe is either 25 or 50fps, North America is 30 or 60fps