In my morning commute, there is a two-lane each way road that leads into downtown. This road is fairly busy, but the traffic usually flows along this road quite well each morning. Sometimes, there is a bike going down the middle of one of the lanes; the traffic piles up behind the bike, and cars dart into the other (full) lane to get around it. This bike is creating a traffic hazard.
Sure, the car drivers could patiently wait for the bike and not dart into the other lane to try to go around it, but let’s stay in the world of what people actually do here. Even if the drivers were to act out of character and be patient, the cyclist is still creating a dangerous traffic condition. I don’t see a solution for these kinds of problems.
And let’s not forget that attitudes are cumulative, too. It’s not a case of a driver being inconvenienced by a cyclist once in their lifetime; in my commute, it’s more like once a day. And you make an excellent point, lawoot - this is part of what cheeses drivers off. Cyclists pick and choose which laws they will respect, then expect drivers to respect them.