I Do not suspect you of trying to dis Noront but I do suspect your broker's comments.

Half of percent Ni is 11 pounds, that represents $100-120 dollars. Operating costs are
expected to be $120. So that covers those costs therefore it is most logical to use that
figure as a cut-off.
Many companies when estimating an economical resource usually use $ values a bit below average operating costs as the cut-off.

But more important aspect that you and possibly these brokers ( probably not, just an excuse on their part) neglect or deny is that we do not have JUST Nickel but other metals (Cu,Pt,Pd) which significantly contribute to the value of the resource. Any one of those pays for excavation and any other pays for processing and overhead. Third is pure profit along with the nickel.

Granted once we go to greater depths, the operating cost rise however even if they doubled the other metals cover that and the nickel is still for free. Sooo... in this case 0% would still be an excusable cut-off level, however it would not be politically correct because those very brokers and the like would be all over Noront for doing so. In my opinion unjustifyingly.
I have no mining experience so this is all conjecture on my part.