Once in a while the reading initiated an argument, and those I present below.
The answer is – instability of immeasurable states.
The Core Assumption of Every Known Single-Photon Experiment Is Wrong
The mission (i.e. the reason for existence) of science as a human practice is making reliable predictions.
The mission of a scientists as an agent of that human practice is discovering the truth about the universe and representing it in a testable form (e.g. verifiable, or falsifiable).
When a faculty tells students "Quantum Mechanics is a complete theory, and it means this ..." he or she is simply lying - hence, he or she stops being a scientist. The truth (the fact) is that there are (exist, whether one likes it or not) different views on the state of Quantum Mechanics, and denying that fact is not a scientific action.
A mere fact that someone is involved in a scientific research does not automatically makes that one a scientists.