Agree wholeheartedly...there have been too many polls lately which are irrelevent to anyone outside the US.
So... Scotland, Ireland, France, and Canada are part of the US now? Interesting. And non-Americans say we don't know geography.
Like all American "Traditions", Trick or Treat is a bastardised version of something else, an amalgam of traditions from various place lumped in to one homogenised whole. Most of those traditions come from Gaelic parts of the UK - thats would be most (but not all) of Scotland, Ireland, and Wales - those from the non-Gealic areas wouldn't know about the origins of the practice, and would therefore regard the whole thing, along with its implied threat of violence should the householders not wish to take part, as yet one more American import.
"Spock, did you see the looks on their faces?" "Yes, Captain, a sort of vacant contentment."