Well,

A friend spend 4 days in Montreal and collected receipts and spent about an hour trying to get refunds but after all the fees and exclusions, he ended up getting 7.50$ lol. He said it was not worth the trouble...

But this would have some impact on tourism since it has already been impacted by the high C$, document control tighten and now no GST refunds. I think someone who really want to come to Canada would not be stopped by maybe spend a little less. For those undecided, it may end up tipping the scale for someone in their choice of destination.