You sound like you haven't tried either MDMA or mushrooms from reading your post. I can't speak for everyone but the stuff you think is 'all bullshit' seems to be pretty common experience even among people who don't know Terrence McKenna or George Harrison from lil Jeffy Sessions.

And psychedelic use has been deeply ingrained in various human cultures all over the world for thousands (tens of thousands? hundreds of thousands?) of years. Taking psychedelics as part of a religious ceremony or ritual to rid oneself of suffering is part of indigenous traditions in the Americas, Europe, Africa, Asia and Australia/Oceania.

I'd say the historical traditions and these new studies should convince even you that there is no fad involved in human psychotropic use.