I must say as someone who uses a bus in London on an almost daily basis that orderly queues are very rare indeed. Buses are so crowded and people know if they do try and queue orderly their politeness is not going to be rewarded when loads of people barge to the front. Also with the frequency of buses in London you can easily find the bus you want to have to stop behind another bus so if you stand in line by the stop then you'll be the last on.
Oddly enough I remember in Edinburgh the bus drivers would never let pax on until they reached the actual bus stop, so if there was another bus there you'd have to wait for it to move off. Good for those queueing but does slow things down.
In Newcastle the drivers would tend to open their door stopped behind the other bus (like in London) but there's not a mad dash for the door and people try and more or less stay in order (although it's a long time since I've used a bus in Newcastle so manners may have gone downhill here too).