Do you live in sprawling suburbia? In a lot of major cities it's fairly safe, and it becomes safer the more people bike. What's stopping people is that it's perceived as being risky. I don't think we need to abolish helmets for that, but the perception that you will die of head trauma if you're riding a few blocks to the coffee shop is a bit much.
Suburbia definitely contributes to this problem with large multi-lane roads, hostile to both cyclists and pedestrians alike. A lot of their cycling projects also seem to be focused on multi-use paths, which are unlikely to bring up the count of commuter cyclists. They're poor to use as transportation or training options, which often leaves suburban drivers confused or frustrated when "there's a perfectly good path for you over there."
