Just to keep a good discussion going:

It makes more sense for the other carriers to feed into their hubs than for AC to do it.
In other words, BA would make more money on YEG-LHR because there is no inbound feed worth talking about in YEG for anybody and yet BA could feed their short and long-haul markets and keep the whole ticket value. AC on the other hand carries the passenger to LHR and then has to split the ticket value with another carrier. Same goes for UA-DEN, AA-ORD, etc.

question:
Why did the Mayor and the Airport Authority not berate WestJet when they started YXE-YOW and yet YEG does not have anything better than a 2 stop?
answer:
Because there is no mileage in talking against any other airline but AC.

On the same track look at Conquests announcement today about their future plans.
YVR 12 flights per week
YYC 12 flights per week
YWG 10
YHZ 10
YYT 10
as well as "frequent" service to other cities.
Edmonton is included as one of the other 5 also-rans in Conquests world.

Delta served LAX non-stop prior [and a little while after] the start of the Salt Lake hub. Actually, was it still Western Airlines then?? I can't think which one started the SLC hub.