The same question from my side - "all" should be used with plural or with something which can be countable. If there is a country it should be "whole" in my opinion. It can be "All Italians play football", but "All Italy ..." sounds at leasy strange
It's maybe a bit strange in English, but not in Dutch. In some languages you can say that a (whole) country does something, although that is technically not really possible. In German you can also say 'Ganz Italien spielt Fußball'. Does not sound odd at all to my native ears.