Seems unfair to compare a "bad trip to the dentist" to a person experiencing severe psychological effects liking being unable to make human connections and feelings of loneliness for 30 years
Many of these experiences seem to have drastically impacted peoples lives in a very negative way. Much worse than a toothache!
Compare to a lifetime on SSRI medication, or untreated depression, or PTSD. Etc. Etc. On aggregate, people are aware of the difficulties that come with psychedelics and still chose to go through, because the known alternative is in fact much scarier.
Also, I think a lot of the persistant issues people are experiencing are due do the still marginal status of these interventions in our society, where it's still not so common to find people who've been through it for guidance.
I've had bad trips on psychedelics and I actually think they tended to be some of the more beneficial ones for me in the long run.