The NDP already represent a lot of what the majority of Canadians want, but fearmongering about sOciALiSm, and the party having to move more towards the center to try and meet the Liberals halfway has diluted their brand.
The people who would never vote for them anyways think that they're too far left, and the people who used to support them see them as too-eager-to-please to the current Liberal government.
If you could magically snap away people's preconcieved notions and team mentality towards politics, and had them read party policies carte blanche, I think a large portion of Canadians would go NDP, especially if they went back to their traditional policies and mindset.