I think if it was shipping refined oil people would not be as opposed since we can easily deal with those spills but Dil-bit for many is the deal breaker. For me I see the twinning as one of the most realistic projects both in scope and speed of building. But until Dil-bit is out of the picture I cannot support it. Pipelibes with dil-bit flowing through them have been noted to have higher rates of corrosion and breakage in older pipes due to their age and new pipes are showing much higher rates of wear and tear which approaches twice the age of the pipeline. Anyways some interesting reading here. https://www.scientificamerican.com/article/tar-sand-oil-and-pipeline-spill-risk/