I'm not really sure how to answer your question because I don't know what you mean. To me the reason for it doesn't really matter too much. People are opposed to improvements to our city planning and transportation networks. Call it "small mindedness", call it "having been lied to their whole lives", call it "wanting things to stay similar to what they already know", call it what you like, the fact is that they will lobby against improvements like increased density, better bike paths, and reductions in the convenience of cars.

The fact is that neither Amsterdam nor Tokyo got how they are by sheer accident. Amsterdam's case is perhaps more well-known, because they were going down exactly the same route as us in the '60s, until there was a concerted effort to reverse that (a campaign known as "Stop de Kindermoord" or "Stop the Child Murder"), and now it's one of the best cities in the world to get around in.