It is very unfortunate that the Detroit affiliates are what represents the USA to much of Canada. First off, Detroit is the most depressed and one of the most crime-ridden places in the country. The level of violence and urban poverty in Detroit is unmatched by any other big city in North America. As a result, the local newscasts are full of appalling things. Lord knows how many Canadians think that what goes on wholesale in Detroit is typical of every American city. It's not.
Sure, most of our big cities have pockets of poverty and desperation - but Detroit is a post-apocalyptic city. As our cities go, only New Orleans comes as close to being a part of the third world.
Secondly, only 2 of Detroit's big 3 affiliates are decent stations. WWJ is a joke. Last time I checked, they didn't even offer local news. When I last watched them (2 years ago) they were an amateurish operation that looked more like a station serving a city of 50,000. Pretty much any other top 20 market CBS affiliate would be better to offer Canadian viewers.
Boston, Buffalo, New York or Chicago stations would all be better to uplink to Canadian cable providers than Detroit. Certainly more representative of what is "normal."