If the Canadian government didn't have content rules I think the US satellite services would certainly be offering their services here.
Programming content rules are not the reason. BDUs, broadcasters and telecom services must be majority owned by Canadians. There have been joint ventures but foreign ownership and control must be under 50%. Canadian cable companies and telecoms have traditionally been founded and owned by Canadians.
It's one of the few areas where Canadian companies have not been bought out or driven out of business by multinational corporations and it's solely due to Canadian government regulation of the industry. Canada once had a review board to prevent unfavorable foreign buyouts of Canadian companies. That was dismantled in the 1980s. Canada has been losing technology and jobs due to the sale of Canadian companies ever since. Once Canadian companies are sold to multinational corporations, it's not long before jobs and technology are moved to the corporations home country or low wage regions like China. The technology and jobs lost are often created with government grants that were meant to increase Canadian competitiveness in targeted technology sectors and create long term Canadian jobs. The money for the grants comes out of taxpayers pockets. The money from the sale of the companies goes into the pockets of the people who received the grants to create the company. Should they be paying the grant money back when the company is sold?