Could you give any examples? It is definitely true that people are often portrayed as "weird dudes acting alone", however it is much rarer that that is actually true.
Indeed, if you look at attempted or successful assassinations of US presidents, excluding JFK, only Lincoln's assassination involved a conspiracy.
Strangely enough, years later his attorney's argued that he was framed. Even RFK's son, Robert F. Kennedy Jr., believes that Sirhan Sirhan was framed and did not actually conspire to kill RFK. He actually wants Sirhan Sirhan released [0].
[0] https://www.sfchronicle.com/opinion/openforum/article/Robert... [1] https://justiceforrfk.com/index.html
Nobody argues that Sirhan conspired to kill RFK and shot a revolver at him, and very few people question the leadup to that attempt.
Point taken, however, that RFK's assassination is not an unquestioned case of a single deranged individual.
Now one of the most prominent and vocal anti-vaxxers.
"the LSD" way to minimize being the subject to hundreds of hours of interrogations, experiments and abuse by the CIA as a child.
MKUltra was also a series of horrendous, abusive, and unethical psychological experiments conducted (in secret) by the CIA.
Ethically, Murray wasn't, unfortunately, much of an outlier; lots of psychological experimentation in the US during the 50s, 60s, and 70s was horrifying. Although Murray's background and professional history is suggestive, there is no evidence that he or his experiments on Kaczynski were actually part of the MKUltra program.