I assure you this is mostly a set/setting problem and why it's recommended to do with experienced (and more importantly, grounded) facilitators. It can leave you pretty open and suggestable, drinking with a group of lost souls and escapists is not recommended especially if you're new to it. (I've worked at traditional retreat centers and have drank hundreds of times; it's a little funny when someone comes in expecting to be able to build a story and further their escape then have their bubbles burst by a grounded point of view)
IMO This is a dangerous way of thinking. This is the Timothy Leary adage that you are stating. It is not just a "set and setting" issue. Whether or not you have a good or bad trip, or whether you are alongside kind empathetic people or whether what you see is positive or negative does not matter. It has a lot to do with the person individual makeup, sensitivity, ego-centricity, and pre-ingrained beliefs. They do not automatically go away after the trip and the realization. The realizations come into conflict with them. This can very easily be a catastrophic event for some.
I personally think Ayahuasca gives an amazing capacity to see the potential within the universe and within ourselves... it is nearly infinite. However if you deeply understand the world and how mis-aligned it and yourself are from that potential it can create tragedy. If you believe you are responsible for this tragedy it can create catastrophe. I don't mean to over-extend my own experiences too far.
What if there is a book that when you read it you would know for 100% certainty when you die there is no hell, and only infinite peace, unless you wanted to go back into hell. Should everybody read that book?
That's what taking Ayahuasca felt like for me. I don't think it is great to do for everyone. I'm curious to hear your thoughts as you have much more experience than me. I had a lot of challenges after taking it.
I think you're right that those "type-A" folks with more rigid minds have some trouble with integration ("catastrophe"/"tragedy"). Our (what I'd call the traditional) approach is very holistic- this path is a whole modality and lifestyle of its own, it's not a haphazard magic pill you do once but a tool to look under the hood every once in a while to see where you're at and what energies are influencing you the most. The earlier sessions can seem catastrophic without the right context (that is, there is usually a lot of low-hanging fruit that comes off when you first come to ayahuasca- you usually have to feel/fully experience these energies to process them before they can be released). You might see/realize that you have a lot of work ahead of you which can be discouraging/overwhelming for sure. More serious cases (long term depression etc) might even want to start out with very small doses (or not at all) and let the ayahuasquero do their work (via icaros, and/or other plants/methods) for a few ceremonies first. (How do you drink the ocean? Sip at a time) In the tradition we work in, drinking ayahuasca is only one part of it. Signing up for a weekend retreat without a well-trained healer can be...counterproductive. The biggest tragedy is casual/new seekers not knowing the landscape- there are many pitfalls and a lot of charlatans, it's probably going to get worse before it gets better with legalization efforts to be honest.
It's self-indulgence essentially, and being around other "drop outs" (I don't really like calling anyone that) can make it seem like it's the right thing to do and you're somehow making progress by just drinking (when you're really just lying to yourself). It's a big trap- spirituality as a fad/fashion. I don't like to blame anyone stuck there (we really all are on our own journey, who's to say if it's right or wrong even if it looks like a big detour to me. Some people just aren't ready to face the truth, but at least being with the medicine will give them ample opportunity).
