I am farting in a thunderstorm, since this argument has been had a million times. Nevertheless, i will explain why i personally worry about the transport. Perhaps the other commenter has different reasons, i don't know.

I currently pay €2 per month for my mobile bill. That is very little money. Notably, that includes no internet/data, but it does include unlimited text messages. Can you see why SMSSecure is something i would want?