I have found that the best way to educate people on the importance of no government backdoors in encryption is to use the example of TSA approved locks.

Everyone knows when they put a TSA lock on their luggage it does almost nothing to improve the security of their luggage. Any serious criminal has a key to TSA locks.

Adding backdoors is like putting a TSA lock on your bank password. It keeps honest people from seeing it but doesn't do much else.