The problem with bluetooth is attention span,we've all been into stores where cashiers are talking into thin air with a bluetooth chained to their face,they dont have a single clue whats going on around them,if i was a thief every time i saw one of those attendants talking with a bluetooth i'd clean the whole place out,then walk right past them & they'd be clueless.
Its not about having both hands on the wheel,its about attention span,people have very little attention span as it is,most people cant focus on 2 things at once,this has been proven over & over again,hell even a thread response thats over a line or two becomes too long to hold peoples attention,driving in a car with a passenger & talking with that passenger while driving is not the same as bluetooth,people using bluetooth have that glazed look in their eyes,its not real,its in thin air & there is no personal contact.
Closely watch the next person you see using a bluetooth & you'll see the deer in the headlights look on their faces,they are in lala land & obliviuos to their surroundings.