True North,

I agree with much of what you say.

However, I really think that an NDP more resolutely progressive than the Liberal Party but pragmatic in its program and presentation can go toe to toe with the Liberals and Conservatives. 

Movements can be devoted to seeking social, economic and political perfection but, by contrast, political Parties, to have a significant impact on the political scene, need to practice the art of the possible and practical.

The Liberals in the 2015 election ran, rhetorically, well to the left of their usual position on many issues only because the NDP posed an existential threat to their very existence as a first rank Federal party. Absent the strength of the NDP, the Liberals would have run and subsequently governed well to the right as this would have been the best tactic against the Harper Conservatives.

The Layton/Mulcair approach works best for the NDP and for Canada generally.