What infuriates me the most is that is such a blind, selfish, first world argument. It assumes freedom of speech is granted, ubiquitous, and irreversible, so those who want extra protection must be criminals.
In some countries you can be killed for your political views. You can also be killed for what you are -- gay, for example.
Anyway, in most cases the person who said that is a complete hypocrite, like a politician/businessman who wants to ban encryption to be able to spy on their competitors, not to "protect children".
That's even a higher level of blindness. Those people understand how the world works. They know that hackings, theft, revolutions, and coups d'etat exist, and those who once were righteous, legal and legitimate may be prosecuted.
What if there were a revolution and the new government decided that now being a sports fan were illegal? That new government may have access to apparently innocent communications where people discussed sports events. Communications that were legally intercepted and innocent in one scenario may be life-threatening if laws change.
That's why we need encryption, that's why all person-to-person communications must be private (we can discuss the transparency degree for governments communications), and that's why governments must find some other way of fighting crime than just exposing everybody naked to make it easier to pick the bad apples.
Sorry for the rant, but encryption is saving lives of gays, illegitimately prosecuted politicians and such. Banning it with lame excuses is short-sighted and may backfire some day.