Why Don't We Have an Incident Repository?
Steve Bellovin and I provided some “Input to the Commission on Enhancing National Cybersecurity.” It opens:
We are writing after 25 years of calls for a “NTSB for Security” have failed to result in action. As early as 1991, a National Research Council report called for “build[ing] a repository of incident data” and said “one possible model for data collection is the incident reporting system administered by the National Transportation Safety Board.”  The calls for more data about incidents have continued, including by us [2, 3].
The lack of a repository of incident data impacts our ability to answer or assess many of your questions, and our key recommendation is that the failure to establish such a repository is, in and of itself, worthy of study. There are many factors in the realm of folklore as to why we do not have a repository, but no rigorous answer. Thus, our answer to your question 4 (“What can or should be done now or within the next 1-2 years to better address the challenges?”) is to study what factors have inhibited the creation of a repository of incident data, and our answer to question 5 (“what should be done over a decade?”) is to establish one. Commercial air travel is so incredibly safe today precisely because of decades of accident investigations, investigations that have helped plane manufacturers, airlines, and pilots learn from previous failures.