[damarquis]

I think it is mainly a logistical issue. The problem is that encryption keys are a single point of failure. IT practices at most businesses would have to be very rigorous before a design with a single point of failure for any significant part of the IT infrastructure could even be remotely considered.

Changing business practices to decrease the risk of using end-to-encryption to an acceptable level has an associated cost which, at most companies, probably dwarfs the cost of its technical implementation.