c'mon LC, they are not "equal". The passenger can actually alert you to an evolving situation on the road, and is a stakeholder in your safe driving
The person on the other end of the phone just keeps yammering obliviously and won't know when to shut up.
There has been at least one study that compares talking on a phone while driving with drinking and driving and found them to be similiar risk levels. Is this not well known?