Mozilla could take great strides towards this type of phone if they cared. Integrate tor, Whisper Systems RedPhone and SercureText, HTML tracking disabled, etc. I'm surprised their Firefox OS looks and works so much like every other phone out there.
Mozilla would have an awful lot of security work to do. If you check the CVEs for Firefox, there was, on average, a remote code execution vulnerability each week in the last 3 months.
