Apollo30
Root Cause Analysis is just a generic name for a cluster of tools. It is used extensively, if badly, in the UK Health Service. The individual components are still used in aviation investigation - even if they are not called 'RCA'.
The problem with 'root cause' is deciding when to stop asking questions. And in very messy accidents like Colgan there will be multiple 'root causes' each underpinning a particular influencing factor.
For example, the use of a third party training provider did not cause the crash. But such companies tend to train to the minimum necessary to meet the check ride. Companies can actually ask for more than the minimum and they can also ask for the 'one size fits all' course to be tailored to company needs ... but this costs money. So, here is a thread that could be explored to establish some 'root causes' of the influencing factor but which would not be considered a root cause of the accident.