The background differs between countries. In UK football is the most spectacular sport. So it is normal for all countries of UK like Scotland and wales to have some football matches. In Canada the spread of the football tournament as wide as possible is implemented by having football matches in 2 biggest cities after Toronto (Montreal and Ottawa). Οntario also is the most populous province so its logical to have there more than one stadiums. I dont think that this spread could satisfied having matches in greater distances (that would create other problems) and considering that in that regions football isn't more popular than the cities mentioned.
Just think this.
Ontario's area is 1,076,395 km2 . UK's area is 243,610 km2