One theory is that as more people cycle, the more we, the important people, will expect bicycles. That's true, but it doesn't mean we welcome them. Instead it just makes us more frustrated.
Take this video of MJ06OSJ, going up Cotham Hill. They've been held up by a line of bicycles, and when they do finally a chance to overtake, there's another bicycle coming in the other directi0n. What to do?
As the video shows, the correct action is: continue anyway. If you've been held up by one bicyclist, you may as well punish another with a near death experience. It may discourage them from trying the same trick next time.