Because we don't have to.
We have the resources and more importantly the moral belief that we can earn our way honestly .
So are you saying that by trading frfeely with Mexico, Canada is unjustly exploiting poor Mexicans?
I challenge you to ask any Mexican worker who's job depends on free trade with Canada whether he would like Canada to raise our tariffs against Mexico.
What are you going to blame his answwer on: Stockholm syndrome?