Why would the CIA want to poison American citizens with LSD and other worse things? Or sell drugs to fund terrorists? Or support terrorists in general? Or the ATF sell guns to the cartels? Seems like law enforcement and intelligence in the USA has an addiction to ramming forks into sockets- in the metaphorical sense.
For each one of these things, there were actual reasons. LSD and other stuff? Other than psychic power testing, it was mostly too see the influences of them on the mind for hopeful use in interrogation or other useful side affects. Cocaine will keep you alert all day for example. They needed to determine if that was useful to give to soldiers to make them more effective, or if it would have problems.
As for terrorists, funding Mujahedeen (as they were then kindly referred to) was instrumental in getting the USSR to fall, as they new that the economy didn't work, and needed to apply constant stressors. It was enormously successful and definitely the right decision, it just had unfortunate effects in the future, that should have been dealt with by Clinton.
As for the ATF, honestly, I sorta see the appeal: You know they have all the guns they could ever want. Giving them more isn't really the issue. In exchange, by tracking where they are found, one can try to trace supply chains and gun running. Now obviously this has flaws, but one can see the rationale.
And together we see the basic problem: good ideas, iffy on the execution.
And why wouldn't they? Just more targets so that they can justify their jobs.
Now Waco? That was (attempted) job justification. But since 9/11, almost no TLA needs job justification anymore.