Presumably the fact that experimenting on oneself is not considered particularly ethical or repeatable for science?
That being said one claim here would be that allowing self-experimentation would pressure people into self experimenting due to how our academia and labs are structured these days i.e. a junior scientists could be pressured into self experimentation by their superiors. So this is definitely not as clear-cut as one might think.
As someone who suffered badly with ulcers in my teens I'm particularly grateful for his work. One course of antibiotics and I never had that problem again.
More so for him and his collaborator having dinner each year when the Nobel prizes were announced in anticipation of the call from the Nobel Prize Committee. Legends.
If people get rewarded for self experimentation, either directly with prices or indirectly with fame and success, more people will try do it. That certainly does raise ethical concerns. It worked out for people you mentioned but there will be many others who might harm themselves doing it.
In the case of self-testing it raises concerns of objectivity, not just in terms of perception and observation but with regards to bias and intent, throwing into question the results and reasons for the study.
But maybe I'm reading too much into it.
Also, to get stronger results you would probably want to conduct the experiment on participants who don't have an expectation of seeing little people, so that rules out locals or people who heard of or eaten the mushroom before.
Something isn’t ethical or unethical, somebody just doesn’t like it. They might have a reason for it at best.
There are very strict rules for scientific experiments _because_ we know that without them, just guided by "common sense" or "be reasonable", someone would get blinded by ambition or "the potential" and go further than the majority want to accept.
Anyone can "experiment" without it being an accepted scientific experiment. But then they're personally responsible for any and all bad outcomes. If you follow the rules and get the experiment pre-approved, you'll likely be covered by your employer's insurance and free from criminal liability . That's a very good incentive.
I agree there ought to be rules, but ethics is just a word to make things sound fair when it’s just an authoritative decision, often taking bad arguments (like religious ones or public misconceptions) unnecessarily into account.