I'd be willing to bet that if you had asked to change to YXE-YYC-YVR-LAX or skipping YVR entirely, you would have had more success. But adding what they see as 2 extra segments to go exactly nowhere isn't going to happen. Yes, the fares might be similar, but there's the added fuel cost and potential missed connction headaches in shipping you to YEG and back for no reason (in their view).

While I appreciate any and all efforts for extra segments and status miles, as soon as you added a backtrack, it was a deal breaker. And in this case, I'm afraid I'd have to side with AC...