@timbray Thank you, Tim. While it is implicit in your comments about the mathematics, it is worth making explicit that even getting rid of signal doesn't ensure the bad guys don't encrypt all their messages. They just put some bright people to re-apply the mathematics in a new (not publicly available, and more difficult for "law enforcement" to access) app.
So making a hole in signal means that bad people get good people's data, but "law enforcement" doesn't get the bad people's data anyway.