Compare this with actual midairs amongst airline transport aircraft. 1959 Grand Canyon, 1976 Zagreb, 1978 San Diego, 1985 Cerritos. And then, since the advent of TCAS, 1995 Namibia (involving a German military machine which I do not believe was TCAS-equipped), 1996 New Delhi, 2002 Überlingen and 2006 Amazonas. That is 4 before the advent of TCAS (mandated 1991, I believe) and 4 since (16 years).
I think PBL is actually missing a few midairs in the above count. According to
www.airsafe.com, there were quite a few others in the pre TCAS period, namely:
1960, AF Caravelle and light a/c, Paris, France.
1960, UA DC-8 and a Lockheed Constellation, New York, USA
1967 TWA DC-9 and light a/c, near Urbana, OH, USA
1967 Piedmont 727 and light a/c, near Hendersonville NC, USA
1971 Allegheny DC-9 and light a/c, near Fairland IN, USA
1971 Hughes Airwest DC-9 and US Navy fighter, nr Duarte CA, USA
1971 ANA 727 and jet fighter, Honshu, Japan
1973 Iberia DC-9 and Spantax CV-990, Nantes, France
1978 Nigeria Airways F28 and light a/c, Lagos, Nigeria
1992 Libyan Arab 727 and fighter a/c, nr Tripoli, Libya
Nearly 800 people were killed in these 10 collisions. PBL, don´t you think you should have included these, instead of only the 4 examples you cite in your argument?