The author does make some valid criticisms of these studies, however he also displays moar than little personal bias, what with mumble jumbling the entire field of psychotherapy.
What he says regarding patient selection and misrepresenting of severity of symptoms/other studies is completely valid, from what I can tell without taking the time to read those other studies in their entirety. However, I'm not on board with him trying to poo-poo the researchers for taking care to design an appropriate set and setting, any psychedelic user knows this is vital to the experience. Putting aside whatever personal biases one may have about the use of Tibetan artwork, Buddhas, and playlists, the intention to create an appropriate safe and beautiful environment for the sessions is to be commended.
He also tries to criticize the researchers for using a randomized, double-blind, placebo controlled, methodology. Sure it's pretty easy to tell psilocybin from a placebo, but that in no way invalidates this methodology. I'm curious as to what methodology he would propose be used instead.
The real agenda is hinted at in the beginning with the co-opting death comment, and revealed fully at the end in the section quoted in the OP. The author appears to have some sort of personal grudge against psychiatry and is airing it out on his blog in the guise of a critique of these psilocybin studies. I actually do agree with him that death/spirituality/mortality isn't really in the realm of psychiatry and I'm in agreement that responsible adults should be able to utilize psilocybin outside of a therapeutic/clinical context. While some of the critiques are valid and the author does make some good points that I ultimately agree with, his presentation and inherent biases weaken his case significantly.
This really gives way to a larger discussion though, and that is, how will we address the re-integration of psychedelics back into academia and the broader cultural dialogue as we move toward their impending legalization?
In the aftermath of World War II, LSD took the psychiatric world by storm. Researchers and therapists all over the globe were investigating it and using it in their practices (and eating it themselves and sharing it with their friends at dinner parties). Throughout the 1950's and early 1960's, thousands and thousands of people around the world took LSD in a clinical context as a part of psycho-therapeutic treatment. It was quite hip to undergo this type of therapy amongst the movers and shakers of the day. Then it escaped the clinic (and the socialite dinner parties) and you all know the story from there, Tim Leary, Furthur, a few hundred million stolen faces and half a century of repressive prohibition.
Realistically, with the recent renaissance in psychedelic research and the strong forward push toward legalized psychedelic therapy, we are simply picking up where we left off. 50 years later we finally put the mind tools back in the hands of the mind researchers. Despite misgivings about institutional control of psychedelics (we'll address this in a moment), this is a good thing! We are finally opening up the "behavioral sciences" to the black box of the mind, and taking the first steps to recover from the crippling blow 5 decades of prohibition of these substances has taken on the study of the psyche.
Now onto the big secret, and the reason why anxiety about institutional control of psychedelics is nonsensical. In the early 1960's if you wanted to try psilocybin, you either went to Huatla or scored some of Sandoz little pink pills through your doctor or your dealer. Now there are hundreds of suppliers of spores and mycology supplies, thousands of grow teks, logs, and methods, and millions of photos and pages assisting with wild mushroom identification documented online. The psychiatrist down at the local MAPS clinic doing psychotherapy with synthetic psilocybin in no way whatsoever effects the ability of a person to access psilocybin in the 21st century.
Of course, there is the issue that the person picking out in the pasture or out of a plastic tub faces possible legal consequences that the therapist does not. That is a personal liberty issue for social and political action however, well aside from medical and scientific pursuits, which IMO we should also be lending our support to as well. With time and research, and appropriate action/activism, as the social climate changes, we will get entheogenic liberty. Remember that cannabis went medical before it went recreational. Let's welcome all avenues that move us forward in such backward thinking times.