I say worry less about what people think and ride more. The only thing that is going to change public opinion is for cycling and cycle commuting to become "normal". When enough people are doing it that is no longer an oddity, the respect will come. Studies continually show that the more people are cycling, the safer it gets.

When I started riding to work, everyone here thought I was nuts. Now there are four people here who are asking me about how to get started. One guy bought a bike and is working on endurance. Three others have asked me to help them plan a route. Several others have said they would like to, but they they live too far or have kids to get to school and other complications that make bike commuting difficult. Only a couple of people still make comments about how crazy it is to ride a bike to work.

You can only be responsible for what you do. Do your thing and eventually others may come around. If not, oh well, there's not much you can do to persuade them anyway.