I'm not sure if you're familiar with Vancouver but outside of the small downtown core, there isn't much zoning for density. Government policy has created a supply shortage.

However, condos come with their own issues as well. There has been a building boom in Toronto that has it owns issues.. http://www.cbc.ca/news/canada/toronto/fears-that-shoddy-toro....

I think urban planning is more complicated than simply increasing supply.