For those who have not read some of Jolly Girl's other threads, I will simply point out that I'm pretty sure she is familiar with recurrent training requirements.
I think both she and JohnRaynor make two valid points, which together may define the issue. The medical profession is learning a great deal from aviation in the context of threat and error management, communication, and so forth. Hopefully, their concept of the impact fatigue has on human performance will eventually normalize with everyone else's (perhaps they can grab the FAA by the arm on the way by).
However, it is worth considering a couple of other aspects. First, an M.D. is an advanced degree in a science discipline. Because a bachelor's degree generally doesn't require you to do independent, published research, it often doesn't convey a real sense of continuing education. Many people understand this anyway, but a requirement to either defend original research or at least make judgments based on original research goes a long way, I think, toward developing lifelong habits of continued education.
Second, the medical community has, over the past several hundred years, generally convinced the public that medicine is not perfect. It is possible for the doctor to do everything correctly and still lose the patient (notwithstanding contemporary litigation trends). Patients will still come to the doctor because there is hope, indeed a good chance, of success.
That argument won't wash in aviation. In order to get anyone on the airplane in the first place, we had to convince the public that we were perfect. Doing everything right and still losing the airplane doesn't quite cut it...the public won't be back for another try. Unfortunately, like most people, we tend to believe our own BS. Thus, a significant number of pilots will learn incrementally from experience (which they can easily interpret incorrectly) and tend to reject learning from more advanced research. The airline will only provide the absolute minimum of training, and is loathe to provide information beyond that which it can defend in court. Brief forays into advanced training, such as CRM or upset recovery, occur but within a few years tend to devolve to regulatory minimums.
In the end, you can't have a better pilot. This is the same argument we get into vis-a-vis seniority versus merit promotion. We are all rated and qualified to the same standard. There is no way to measure any standard above that. We can't tell the public that John Q. is a better pilot that Joe P., because the public would want to know why we even let Joe P. in the cockpit. We all know that both are more than competent, or maybe not, but we have no metric we could possibly use to define it beyond the ATP, first class medical and the six month check.
Therefore, it takes extraordinary effort on the pilot's part to educate himself. His company won't provide the material, and few books are published that address the profession in a meaningful way (not since Davies' Handling the Big Jets). The manufacturers actually provide a lot of very useful material, but the line pilot generally doesn't have access to it. The next problem is that, once he has gone outside and studied various issues to an advanced level, how does the pilot cope with his company's SOPs when they do not conform with the best practices? After all, compliance is an essential part of TEM, but when the SOP is marginal and you know it, what to do?
I suspect that a lot of pilots decide that it is better to spend more time on the boat and let the company tell them what they need to know. I don't agree with that, but the older I get, the more I understand it.