Calgary's +15 is elevated walkways connecting all the office buildings in downtown, not another shopping levels like the underground cities in Toronto and Montreal. Winnipeg, Edmonton and even Regina have many skywalks as well.Calgary has the +15. It's like P.A.T.H but elevated. I've heard Ottawa's Carleton University has one but it's merely bare bone tunnels lined with lockers.
When you're in a rush to get from your office to your train you could care less about feeling the breeze and more about the fasted route from point A-B. Also after the first few snow falls the novelty of walking around in the white stuff wears off.Why would somebody not want to see the sun, feel the breeze, get a little wet from the rain, walk on the snow ?
Maybe it would be suitable in the far north or in some deserts, though.