That's because Australians are invading Westerner Canada resort towns at the moment, and we just want them to go back home and stop stealing jobs from the traditional demographic that takes low paying jobs out West, Atlantic Canadians. We need to build a wall on our Western border to keep the wallabies out, and we'll get the kiwis to pay for it. Go to a ski resort in Banff, Canmore, Kelowna or Kamloops and all you hear are Australian accents. Cafes there sell foreign atrocities like flat whites and "brekkie sandwitches" and you're liable to have a conversation about how Australia beat India in the Cricket world cup on the chairlift (I really did have a conversation about the last Cricket world cup final with someone from Brisbane on a chairlift in Kelowna two weeks ago xD )
...more seriously I'm not sure where you see animosity towards Australian here.