I persevere with this thread, particularly as the issue is of great importance to all of the industry.
ACAS relies on appropriate behaviour of both parties in the event of a conflict, thus there is need for a knowledgeable, universal, well discipline approach to flight operations.
The availability of ACAS in small / GA aircraft implies that those pilots also require a similar high standard of operation (with respect to ACAS) to those in commercial operations.
Whereas a pilot of a small/GA aircraft, with poor understanding of some basic aspect or who has a macho attitude, might suffer a landing (or any other) accident, the result affects only that individual and hopefully no one else. But an inappropriate response to ACAS could result in an accident involving an unwitting third party including many passengers in a commercial aircraft.
If a GA pilot decides not to follow an RA then the commercial safety situation may be no better than it was when the need for ACAS was first noted – Cessna 172 / MD 80 collision.
I am not suggesting that all small / GA operators lack operating qualities, indeed the vast majority (as have commercial pilots before hand) have demonstrated the necessary skills, and strive to improve them before moving on to larger aircraft.
The issues are the immaturity of some people, their reluctance to learn, or poor attitudes in an operational climate where there is little or no oversight, operator / regulatory control, or a second crew member to monitor. Worst still is that a few, hopefully very few, might progress to the very light jets with opportunity to really mix with the larger aircraft.