1) When asked, people may say they want security and privacy - but in practice convenience and functionality win.

2) Among people who genuinely need secure communications, encrypting the content of calls/texts is good, but isn't normally sufficient - they're still vulnerable to traffic analysis.

By traffic analysis I mean that even though the adversary can't read the content, they can still figure out things like:

"Mr X is the ring-leader of the freedom fighters since his phone is used to send encrypted messages to several other phones, which then send messages on to several other phones."

"Mr Y is guilty of orchestrating the protests since we saw a strong correlation between the times of the protests and messages coming from his phone."

So I'm not sure how popular the product would actually be. Unless we can somehow solve the traffic analysis problem.