I think someone belives that key-logging happens in the actual keys.
First they were found in one big bag, because the keyboards were "shredded" to protect the sensitive data.
Then they were found individualy bagged, to forensicly preserve the data for later recovery.
There seem to be users around that would think that sort of thing.
I think it's a form of cathartic vengeance. An early story involved someone telling Airz that if Airz would disable a door alarm so they could take frequent smoke breaks, the keyboard problem would just "go away." Since disabling the door alarm was a terrible idea, Airz didn't do that. So they're smashing keyboards because they know it comes out of the IT budget.