You're assuming that everyone being frozen is "equal". Hate to say it but people like this girl will be unfrozen to see what happens long before they bring out the brains of Steve Jobs and the like.
Make encrypting an email cost something. not necessarily money. kinda like minimg bitcoints but instead of getting bitcoins, you get to encrypt and send an email.
Why would he not rate his own app 5 stars? Same reason every presidential candidate ever says they are going to win the election. It makes no sense to say otherwise.