Costco is a great American success story. America itself is a free enterprise, capitalist success story that has been struggling to overcome, among other things, it's balance of trade problems. In light of that, why would anyone want to discourage people from other countries spending their money on American goods, particularly in an enthusiastic and persistent way? Obtuse Americans, that's who.
These people are the same people who don't get that if you have a successful business, you created it. Why do I say that? Because they clearly do not understand that customers come first. This isn't about Costco, it's about the money being pumped into the local economy, the extra hiring and jobs created because of the demand. The free market is creating a boom for these people and they don't seem to appreciate it. I can only surmise they they haven't done the cost-benefit analysis of economy versus personal convenience. They haven't realized that a problem of too many customers isn't a bad problem to have - for Costco or for the town.
Thankfully, some people there clearly get it, and Costco itself understands the need to expand. As far as Canadians parking poorly - I have no comment.