Quite interesting, but--no fault of a Director of Cities--this piece misses it.  

Interesting, although a bit of an overstatement: "the affluent and advantaged return to cities, they colonize the best locations ... while the less advantaged are pushed out into the further reaches of the suburbs and exurbs or the disconnected and disadvantaged areas of the city."  In short: a complete reversal of the post-war flight to the 'burbs (when the white-collar "man in the grey flannel suit" took a train to work in a Manhattan tower. Today, he'd walk two blocks.) 

"Ultimately, the solution is more – not less – urbanism."  Misses it. The city is just a symptom of the deeper problem: inequity, spawned in the U.S. and to a great degree in Canada, by that "winner-take-all" approach to economics--and politics. THAT is what needs to change.  When it does, cities will change, too.  Not until then.  Thought the visual on the recent G&M story Ontario housing Quick Fix was apt: a bunch of band-aids.