Vancouver (and Toronto), when looking at the urban centres, boast lower-than-national rates of smoking. Source: http://www.statcan.gc.ca/pub/82-583-x/2011001/article/11575-...
There haven't been "smoking sections" in Vancouver restaurants or bars for years (decades?) and we even ban smoking in public parks ... so I'm surprised to hear your observation. I recognize that I'm likely normalized to my home city but I do travel a lot and it doesn't feel like I come home to any more smoke in my city than I'd experience in San Francisco or Seattle.
One observation that I stand behind is ... in both Canada and the USA, suburban and rural smoking rates are higher than urban.
BUT ... the theory suggested here about tourists and immigrants bringing their habits with them is good. And Vancouver is a tourist destination, which is why I was curious about the neighbourhoods you noticed the smoking in.