I lost count of the number of times flying round NZ that aircraft have appeared in circuit traffic/over the field/right in front of me without having the mind to make a radio call to let other traffic aware of their whereabouts.
Just like I've lost count of the number of totally useless radio calls to "XXX" traffic when the aircraft is no where close to, and not even likely to get close to, that airfields circuit area. A waste of breathe and clutters up the frequency.
I think FL440 was trying to make a point about unnecassary verbal diarrhoea that occurs when some pilots use the radio. CTC are not the only ones.
I take your point about unannounced arrivals at an airfield and if the aircraft is fitted with a radio it should be used, and the pilot making the appropriate calls. Last time I looked it was not a requirement for an aircraft to have a radio when operating at an unattended airfield outside on an MBZ. VFR flying is see and be seen, which mean not relying on the radio for your lookout.