Having lived in both Canada and the US, I think you're mistaken. People own guns in rural parts of Canada, but it isn't common for people to own/have guns in urban parts of the country.
What level of gun ownership would you characterize as "common"? Wikipedia says that there are more than 30 guns per hundred people in Canada. Are you basing your assertions about ownership distribution on casual observation? Perhaps you are not the type of person that others mention guns around.
The author way oversimplified a complex situation. The US and Canada both have high levels of gun ownership. Canada also has significantly higher crime rates in many areas. The US still has higher violent crime rates, but that gap has been closing in recent years as the rate in the US drops.
