In my opinion, the differences are as much for social and cultural reasons as anything else. In this country it is the one big festival of the year when the whole family gets together and celebrates. I have spent Christmases in four (north European) countries and it is much more of a low-key religious event, even if more than usual attention is paid to it by non-Christians. However, it is still just one of a number of religious festivals, albeit one of the more important, so it is not marked out as the big one. There is also, in my opinion, less of the situations of families being split up around the country and ignoring each other most of the year, but making it up by going over the top at Christmas.
So most countries keep on with a near normal life over Christmas, but we go bananas. ‘Got to be with the family as much as possible’ becomes the norm and people just don’t travel.