Based on debriefs I have conducted or listened to, it seems that very few pilots know what power/prop/pitch settings will give them a specific airspeed, at given atmospheric conditions. It could be that the pilots noted in this string are hunting around for the right combination, as is the pilot in front of that plane, and so on. That does not excuse those pilots, nor does it mean that some pilots are simply not paying attention. It is just one more factor to consider.