mercurydancer;
I have spent most of my career in naiveté. Flight safety work is mostly fighting rear-guard actions when in fact a career-development process would resolve many, though not all these issues. While I do not support the notion of the MCPL, like SMS it is not because the training or the concept itself is wrong but because I have no reason to believe that the MCPL will be handled properly by the airlines. Under the heading of "98.6" and the bare minimum the law requires in terms of experience levels, they will consider that anyone licensed to operate the aircraft is "competent".
That is where the "consolidation period" rule-making came from - airlines were pairing newbies with newbies (new on the airplane or new in the business) because they could. Wisdom never entered (or enters) the picture.
I know pilots who began flying transport aircraft at 250hrs and did just fine but that was because, at the time, the airline I worked for had a Second Officer's position and one "learned the ropes" in the back seat...so to speak.
Today, new hires, especially in the regionals, are "qualified" even though they may not have any experience in demanding circumstances.
Aviation is such that most of the time, nothing happens. But Charles Perrow's notions of the organizational accident and Jim Reason's now-familiar expression were meant to convey the notion that disparate circumstances randomly occur and sometimes very close together in time, and result in an otherwise-avoided accident.
I truly desire that aviation was as you blue-sky it! Perhaps a "College of Aviators" which sets standards, issues licences and examines candidates would resolve some of the issues. I think however, that both the medical and legal professions have much to teach anyone actually contemplating such an initiative...