I think your standpoint may well be what the majority considers reasonable, but consider this; nothing stops a criminal from using encryption technology without backdoors. There is no way to ban such technology, because it is already available for free from websites all around the globe, and distributed with free operating systems.

So what you end up with is a gimped encryption technology that is much more vulnerable than what we have now for the common man, and strong encryption (available for free, right now) for everyone with a modicum of know-how.

And how would you implement a global three-key backdoor? Which governments get to participate? Or should each country get their own backdoor for computing devices sold locally? Can I legally buy a computing device from another country and use it here? Can I legally install software of my own choosing?