I haven't studied the exact question you're asking, but as a principle, the kinds of interprovincial trade barriers are exactly barriers to growth of some form or another, as the other member was talking about. As with all things, they help some people while hurting other people. By changing those things there is always a certain amount of angst around those things.
I think the important principle to bear in mind is that if it's good for the economy as a whole, there's room to manoeuvre around cushioning the blow for those who are affected negatively. That's an important thing that is often forgotten.