At the risk of an over simplification, there are two parts to a safe operation:
1) The hands and feet skills
2) The pilot decision making, interpersonal skills with other crewmembers, and personal discipline to adhere to SOPs, limitations ets. These can be loosely grouped under the "human factors" term.
Aviation training has traditionally been all about No 1 with No 2 added on as an after thought.
My personal experience is organisational safety is ultimately completely based on company culture. The organizations that get the most out of CRM are the ones who need it the least. The operators who tolerate or even encourage poor CRM are the ones who will be completely resistant to CRM training. Any courses run will be a total tick in the box and will have zero effect on system safety.
I think CRM "next gen" should be MSRM (manager safety resource management). This industry has not in my opinion done a very good job at presenting the link between management decisons and safety. I think there are lot of managers that truely do not understand the safety consequences of many mangement decisons and policies. A mandatory progran aimed at them will IMO have a positive long term safety impact.
In the short term CRM courses only work the first time. Repeating the same course has IMO zero benefit. If organizations are serious about CRM they should insist on a new supplier for every cycle of CRM training.