Same problem with WMDs: people tend to think there's just tons of chemical and biological weapons which would definitely immediately win wars, and we don't use them because for some reason dying by a bullet is "better" then dying nearly instantly from nerve gas - like that makes a difference.
The reality, again, is that they don't actually work (specifically: they are ineffective against military forces in achieving military objectives, but very effective against civilians who are unlikely to have counter-measures on hand and/or too uncontrollable to be create a useful strategic advantage).
EDIT: Like to drive the point home, in Zero Dark Thirty - which the CIA got to consult on - the line is that a prisoner broke under enhanced interrogation...and while it's true Bin Laden was located by intelligence from a prisoner who was tortured...they didn't get the intelligence from the torture. All the information which was useful was found by regular interrogation before they tortured them.