The Caribbean is just generally difficult to make it work from the west coast of North America, period. When LAX (Southern California is way bigger than the Lower Mainland and closer geographically) can't make the Caribbean work, Western Canada to the Caribbean non-stop just isn't going to happen unless AC decides to operate a route partly for diplomatic purposes. Same thing with BOG, no flights to LAX/SFO, so how would YVR - BOG work out?

Not to mention that being out west, it makes much more sense to go to PVR/SJD/CUN/OGG etc. on vacation instead of heading all the way east to the Caribbean.