The courier companies CAN and DO move mail, however they charge more than 52cents for a letter - I believe Purolator is something along the lines of $10 for a Puroletter, perhaps more.
Yes, Canada Post moves shipped goods - however, they move them by MAIL routes, not by COURIER routes.
With more private citizens becoming involved with shipping items via courier in the past few years, rather than companies, it would be a good idea for the courier companies to take a look at their stats and see if they can work out a closer-to-nominal rate for private citizens moving items between themselves - as opposed to businesses moving shipments between businesses.
I would imagine this would be a slight mega headache to set up and control.
Small businesses will then be saying "but we're just a small company and we only have 3 people working for us and we need a break, can't we ship for private citizen rate with you too?"
Of course, if you're going to be taking on a "cause" to be fighting for, why not take on the Canada Income Tax Act which supposedly was instituted during wartime to help out the country's coffers that were becoming depleted .. and here we are how many decades later still paying it?
:)