The history of psychedelic use in therapy is part of how we got here in the first place. The therapists in the 50s and 60s were engaging in inappropriate behavior with their patients with regularity.
I am very pro psychedelics but the 60s provides an almost endless array of examples of how it can go wrong. Psychedelics basically do not belong in a therapist to patient context because the therapists attracted to that approach have a tendency self-select.
A lot of the modern day gurus and shamen have exactly the same problem.