TechCrunch describes The two misconceptions dominating the encryption debate.
In the first he points out that the government already has access to more data than it's ever had before or knows what to do with:
The majority of global networks – including Facebook, Google, Twitter and Skype – operate with full visibility into user accounts and often their activities, rendering this data available to law enforcement with a warrant request. That includes metadata, a rich unencrypted layer in our expanding profiles – who we talk to, where and how often, where we spend time and with whom, and what our interests are.
Widespread visual surveillance — from cameras on public utility polls and transport to commercial data collectors time-stamping and geo-tagging billions of photos of license plates – supplies an exhaustive picture of ourphysical activity. Law enforcement has access to a historically unprecedented amount of information, capable of mapping out countless connections between people, businesses, locations, and things – sometimes with and sometimes without a warrant.
Current trends in technology are only adding to the pool of data that law enforcement can draw from. When vulnerability is injected into technology used worldwide, it becomes everyone’s liability."
And this will only get worse with the Internet of Things (as more and more things are connected to the Internet). The second is the obvious one, we only want a backdoor for warranted government access; but of course there's no way to enforce that any such backdoor is not also used by bad guys. That's the part that non-technical people have problems understanding or believing (this is not going to be fixed any time soon by smart people trying harder).
John Oliver covered part of this brilliantly and hilariously last night: