No. As a Canadian... I will support knife rights when they support Canadians.
You have every right to choose how you want to spend/donate your money; in this case given that Knife Rights seems to focus the majority, if not all of their efforts in USA, I can see how your lack of support in this matter can be argued as a Canadian.
However, as a fellow Canadian, please consider the following:
The knife community is an international one; the members of BladeForums being a prime example of this. Here you have a place where people from all walks of life who reside in places from around the globe, gather to discuss blades and share their passion for them.
Given that in a fair amount of places, there are various restrictions regarding knives, I think it's in the community's greater interest to support their fellow hobbyists in different locales to
A) Help those who share the same passion for knives enjoy this shared hobby more freely and
B) It helps to set an example/precedent for other areas/locations (for example, with the current shennanigans with our own CBSA, a handy example to have is the Australians who irrc had a law banning flippers or their importation or something along those lines repealed simply because it was an ineffective law for doing anything other than prohibiting flipper knives - or so I've heard
An example that may be of greater interest to you as a Canadian is that when the issue with the CBSA first came into play, there was a lawyer who was raising funds to mount a court challenge here. One of the first (and one of only a few) places this was covered was in an article on Knife news. After reading their article, I decided I too wanted to contribute monetarily and when I went to the fundraising page, the first donor was Knifenews who had contributed $500. I'm willing to bet that the outlet doesn't have a super strong Canadian connection, but were giving to the effort more as fellow enthusiasts supporting us Canadian enthusiasts.
If you don't want to contribute to KnifeRights because they don't often/ever directly fight for change in our backyard, that's ok. But I wouldn't be so quick to discard the organization given all the work they do for fellow enthusiasts just to the South of our border.
Edited for spelling/grammar/clarity.