The bikers I see around here are obviously biking for pleasure (dressed in bikes shorts and tank tops, escorting little kids on their bikes. . .)

We have a paved bike trail close by - 9 miles in one direction I believe. There is plenty of parking available at the trail head on either end. People seem to prefer to bike on our main roads, with no shoulders to speak of, and lots of blind turns, speed limit often 45 mph (so you know traffic is moving faster than that). It's not safe.

Bikers have been involved in traffic accidents, even killed.

I have no idea why they continue to bike on unsafe roads.

And pedestrians? We have pedestrian bridges that cross over very busy roads. What do many pedestrians do? Dodge traffic while crossing the road under the pedestrian bridge. Don't ask me what goes through some people's minds.