I know what you're saying, so I'm sorry for being a little pedantic, but I just have to jump in and point out that there are MANY bike commuters in suburban and rural areas. I lived in Bloomington, Indiana for two years and biked 3 miles into town every day. It was incredible for my health and the countryside is just gorgeous. In many ways it was vastly preferable to my various urban commutes since then.
You're right that the infrastructure is often lacking, but you learn the tricks you need to get your errands done, and there are many of us out there every day building the critical mass to change that.
From the second result in Google: "The average commute in miles for Americans is 16 miles and 26 minutes for one way"
In reality of course, these commute times are all of your own making. Just because politics in the 20th century designed cities a particular way doesn't mean it is now forever set in stone in the 21th.
There are plenty of times when it is too expensive to live near work.
There are plenty of times when housing near work is low income or unsafe.
Until recently I lived about 20km away from my work, and my commute took about 25-30min: 10min walking and 15min on the train. I found this a very nice and relaxing commute; being on public-transport means you can read / browse the web / zone out, and indeed it's a valuable unwind time for me (the walking time is also hugely beneficial in this respect). [The same trip by car takes about 30min with no traffic, or an indeterminate amount of time in typical rush-hour traffic...]
In all honesty Calgary is a hopeless city.
Consider Tokyo: https://maps.google.ca/?ll=35.637209,139.744034&spn=0.502803...
Now compare it to Calgary: https://maps.google.ca/maps?ll=50.988692,-113.841705&spn=0.3...
Keep in mind Tokyo is only the center of that metro area. Tokyo itself is 13M people. The full metro area is 35M! Meanwhile calgary is a mere 1M!
Calgary is just not scaling. If we tried to fit 35M people in Calgary the city limits would start hitting the Rockies! Just as CPUs are hitting limits on the speed of light Calgary is hitting limits on safe highway speeds. Mass transit could be improved but it cannot shrink the city.
The best part was actually looking forward to my commute -- even though I only cycled about once or twice a week. Now I'm so far out of shape, it will take a few months of working out in the gym to get back to what I was doing (and hopefully my knees won't go out again).
You can make of that what you will. I would call it rural.
Your average noncollege town isn't like Bloomington.
(40 km is not a particularly long ride for a recreational biker...)