Overall, I'd like to think of the other cyclists on the road as my biking brethren. We are all disadvantaged users of the road. Even the fixie riders and slow people in expensive carbon fiber bikes.
On the other hand, my wife has to drive through Berkeley, and every so often she calls me up to complain about a cyclist almost running into her. And, usually, it's the cyclists own damn fault. And a number of my friends take public transportation and find themselves walking in the city. And they complain about stupid cyclists riding on the sidewalk and not paying attention.
Generally, I prefer my wife to drive like the cyclist she's overtaking might be me on an unannounced ride. And I prefer to bike like the pedestrian I'm overtaking might be one of my good friends on an unannounced walk. That's a fairly rational way to think, no?
The people who just have to bike like idiots... they are not my biking brethren.