I'm betting the graph is bunk because it doesn't list very many independent breweries, which don't have the same huge penetration that the piss brands do. For fuck's sake, I don't even see Yuengling or Great Lakes and those are pretty huge in Ohio and Kentucky.
I myself am a huge fan of a particular small brewery in my hometown (go Wild Rose!) but they don't represent much more than a drop in the bucket in Canada. They're just not big enough. So I don't project my preferences on others who follow the big brands, but I do recognize that they represent the majority.