I don't think you're putting too much weight on the oil industry or the pipeline.
I do think there is a super stubborn "our way or no way" coming from the west.
As someone from NB, I personally HATE that we import oil from outside Canada. I can't imagine any other Easterner thinking any different.
And yet, I CAN see the West voting to put an end to Quebec forestry and dairy or the auto. Why? Because it's not about industry or people's livelihood, it's about how much the west hates the "east" - which is only Quebec and Ontario, as it's believed to be the opposite going the other direction, that Quebec and Ontario hate the West. If the West could 'tit for tat' those two provinces, they would. And bugger the rest of the East who actually aren't too far removed from the West in a lot of the views. Unfortunately, we're looked down at because our people move out west, "Take jobs" and how dare we do that, then come home.
I see the major problem being a lack of willingness to compromise on both sides. On all sides.
Yeah, Canada's divided, and sadly, cries for separation does not help the issue what so ever and THAT is squarely on the shoulders of the West (and Quebec when it suits them).