I understand it as this : your moral obligation as a technical person is to protect your less computer-savvy users / kinfolks from being unjustly spied.

By increasing the cost of surveillance you force intelligence agencies to make a choice : given widespread enough encryption they would have to decrypt only the real threats and not ordinary citizens.

There is no reason to spy everybody unless you want to model your nation's citizen to be able to influence / control them.

My 2 (euro) cents ;-)