Why do drug manufacturers put their pills in blister-packs that are nearly IMPOSSIBLE to open?

The answer is quite simple. Some years ago, a man murdered his wife with a poisoned capsule (perhaps Tylenol). He put poison in a number of such capsules in his city and returned them to the shelves in stores. He was attempting to hide the murder by implicating an unknown but demented random killer. Of course he was caught. The drug companies and other companies making pills decided to increase the security on their pills so that one could know if someone had tampered with the pills. That is, the wrapping is a protection against some poisoner who did not exist but may come in the future.