It really seems like Canada is in a tough spot economically. They don't have the scale to compete against, say, China or the United States but they want to protect domestic industries against foreign competition and so have enacted trade barriers and other protectionist policies like supporting Bombardier (or the dairy industry or whatever) even if it means higher prices for Canadiens and goes against free trade practices.
In my mind that makes a lot more sense as to why, at least in part, there is the ongoing trade dispute between the US and Canada (whether I agree or disagree with it and how it is handled would be a different matter). The US also seeks to in part protect domestic industries that are being outcompeted by China or face significant regulatory barriers (diary industry in Canada for example, other various exports to the EU, Chinese ban on American technology companies) and so we're winding up in a world where the US is now also putting the hammer down on protecting industries like the EU, China, and seemingly Canada does which is causing a lot of political conflict over trade and jobs.
It seems inevitable that as one or more countries put up trade barriers (EU, Canada, China being some large ones here) the US and others would eventually respond if they found that they were unable to compete on price due to government intervention.