Because if someone says they want your facebook/line/whatever to talk to you, you become a bit of an outcast when you say that you only use secure messaging apps like Signal. People here might be willing to put up with those discussions, but most people don't.

Furthermore, I have huge doubts whenever any US-based company says it's "secure". It's easy to say that. Even on their security page[1], they don't give a clear, straight "yes" to the "is it private?" question. Ask a farmer if his beef comes from real cows and he'll say "yes." Ask a company that makes secure apps if they read your messages, and they say "we use various encryption techniques to prevent unwanted man in the middle attacks and our specific organization name won't read your messages." So sure, they're safe from unwanted attacks and they won't personally read your messages. Governments, well, we won't reference the clear suspect of this question because you know why.

https://support.signal.org/hc/en-us/articles/212477768-Is-it...