It takes a certain intensity to make something different happen. Merely exposing people to new ideas probably isn’t going to be enough if the hoped-for change is in any way an uncomfortable or unfamiliar one—the issue could be out of conscious awareness apart from anything else.
So we need someone to show us how the learning connects with us—how it applies.
Sending people on courses will only take things so far.
For an intervention to be an intervention, somebody needs to intervene. There needs to be a change agent—someone who can deliver help to the system from outside, as W. Edwards Deming might have put it, because “a system is not capable of understanding itself.”
Somebody needs to be close enough to say “this is how the issue applies to you and here’s what you need to do.”
Interventions need an intervener.