I don’t know, I’ve met a decent amount of Canadians over the years, never got any bad vibes from us. I think the problem is America has more than our fair share of assholes, so they approach us a little skeptically, but if you show you’re not an asshole, I think they like us just fine.
Of course, my biases should be disclosed. Most of the Canadians I’ve met have been from roughly the Toronto area, plus a good handful of French Canadians.
Couple of the officers at the border when I went to Montreal were kind of dicks, but I think that’s more of a universal feature of border crossing and customs officials around the world. Once I was there though no one gave me any shit.