The way I see it is, we have a right to privacy. Government overreaches in years past have slowly chipped away at the legal protections of that privacy, and say

The way I see it is, we have a right to privacy. Government overreaches in years past have slowly chipped away at the legal protections of that privacy, and say that, for example, our emails are fair game without a warrant because they're sitting on someone else's server, so we obviously don't care to keep them private. If we encrypt those messages end to end, they can't use that argument, because we're taking clear measures to keep them private even from the server owners. So it destroys a legal argument as well as letting us take back our own privacy and protecting it without relying purely upon an ever weakening legal protection. That's why I do encrypt and advocate encrypting email, not to avoid NSA scrutiny. If one's life were to depend on avoiding such scrutiny, however, the advice in the article may be reasonable.