Are you asserting that the housing affordability index is unchanged in most of Canada in the last 20 years?
Moreover, if you take the time to drill into the actual numbers, you'll find housing affordability is about average relative to historical figures (in terms of percentage income spent on housing) in most urban areas, with the exception of a few major centers (Vancouver, Montreal, Toronto) that are pulling up the national average:
http://www.rbc.com/economics/economic-reports/pdf/canadian-h...
While it does vary by region, according to this we are at a 20 year high nation wide. I guess it all depends on which propoganda you read.
http://business.financialpost.com/real-estate/rbc-says-housi...
"Home affordability in Canada worst in almost 30 years, Toronto’s worst ever, says RBC"