LCI Larry Mysz passed on these links to videos regarding the Door Zone. You may find them helpful in understanding the problem and in relating the importance of Vehicular Cycling (i.e. Defensive Driving) to other cyclists.
At the same time you always run the risk of conveying the overall impression that cycling is not safe. So be it. I would rather be honest about the dangers than a Cycling Pollyanna. Cyclists need also to understand that not every infrastructural “improvement” is without its own set of new dangers.
Bicycle lanes that are “too narrow” (i.e. do not allow the rider to ride outside the “Door Zone” without entering the car lane) should be part of the discussion in the cycling community. They share an equal portion of the blame with inattentive motorists and incautious cyclists when deconstructing the death and injury that result from Door-ing.
Placing too narrow bicycle lanes adjacent to parked cars is “no accident“.