Systems thinking has destroyed the idea of single cause thinking from the 16th century. Systems thinking has been on a roll since Bertalanffy wrote General Systems Theory in 1968. In spite of systems thinking, the use of "root cause" phrase persists.
Psychologically, there is an upside and downside of the phrase “Root Cause Analysis (RCA).” The upside, the illusion of single cause thinking gives people hope. It sends the message that one thing is going on and they can handle that. On the downside, the mental image of a “root cause,” leads people to finding a cause. I once watched in horror as a Master Black Belt (MBB) led a group of engineers in a high-tech company through a multi-voting exercise on an Ishikawa Diagram. Once the MBB had all the votes, they focused on the “top cause.” There was a short plan put together to investigate this single "cause." Since I was visiting, I was silent until someone asked me what I thought. I asked a question about the possible covariance of factors for the application being discussed. After one engineer that the factors do indeed interact, they got back to reality. Rather than one factor, they needed to consider multiple factors in a designed experiment.
There is hope. People are waking up! In 2015, The National Patient Safety Foundation exposed many of the problems with the myth of "Root Cause Analysis:" From the report:
The effort to restore systems thinking and 21st century science continued in February, 2017 with publication by Kiran Gupta, MD, MPH, and Audrey Lyndon, PhD, entitled Rethinking Root Cause Analysis. This paper has some great tables that describe the various problems associated with RCA. The authors are working with reference to 2015 paper referenced before. Their paper can be found here:
Recently, Duncan Mackillop observed on LinkedIn: "I wonder what the "root cause" is of something that's gone right? After all, things go right and things go wrong for the same reasons." Typically, "root cause" thinking is only invoked when something has gone wrong. Duncan's reframing shows how limited single cause thinking is to any endeavor beyond the very simplistic.