Ixixly, you state,
I don't particularly agree with Dicks assertion of the congestion of Area Frequency causing a Mid-Air due to missed ATC instructions
Ixixly, I have never mentioned that it is a congestion problem – it is just a probability problem. That is, one important call is blocked out some time in the next five or ten years resulting in an horrendous accident.
Just why air traffic controllers would want VFR aircraft taxiing and in the circuit area of aerodromes giving non-directed calls on air traffic control frequencies that are used for separation is beyond me.
I will say it again – no, not congestion, just simply one call at the wrong time. That is how accidents are caused.