Rolling blockade ?? Really ???
It is entirely safer to execute the correct overtaking manouvre: if that means you wait a little: so be it. I find it sad that you have to be somewere so soon that you can disregard the safety of other road users.
Do you get angry if electric wheelchairs hold you up as well??
You are assuming that its possible to find said moment to perform a proper overtaking procedure with a bicycle wobbling around the road in front whilst in a busy city. I shouldn't need to do this, theres plenty of room for my car to pass with ample buffer space, should the cyclist choose to keep a steady line reasonably close to the kerb.
So what your saying to the hundreds of people being delayed by your rolling roadblock is "if I'm holding you up, so what"
Other road users travelling at that speed such as road sweepers and milk floats look for opportunities to pull in aware of the traffic build up behind them and let them past. So often I see cyclists doing the opposite, making deliberate steps moving out further into the road to prevent other vehicles passing. (thats if they have any awareness of their surroundings at all and haven't got their ipod running).
Angry at electric wheelchairs? Honestly... yes, sometimes the odd one has been known to get up my nose. Just because someone might have a physical disability, it doesnt excuse or justify ignorant behaviour, same as if you happen to be wearing lycra.
I think cyclists are probably the most hated road users, simply because on the whole (there are exceptions) they are very poor road users. They disregard laws, are inconsifderate to other road users and generally present themselves as hazards, forcing their way in front of others and with little observation or anticipation. Then they have the cheek to suggest others are endangering their safety.
Those that deliberately ride two abreast in a bid to prevent other road users passing are causing an obstruction. They should be taken aside and given a good old fashioned birching to prevent them doing it ever again.