With your analogy, BA, AA, United and every other tom dick or hairy should have to have a base in Toronto to fly there. Give your head a shake.
Ah.....no.
The airlines you mention are all already based in countries similar in Canada in the ways I mentioned. Some might disagree but last I checked Britain and the US are still forms of participatory democracies and thus bear more than a faint resemblance to the way things are in Canada.
If you actually lived in the UAE you would realize it's a whole other ball game and thus, comparing apples to oranges. While I would not be so presumptuous as to ask the Middle East to leave their medieval socio/political systems in the past, I would definitely fight to not have them not drag the world airline industry down to their level.
In other words, comparing BA/AA/UA to EK is pure bs.