Allowing a well-designed and well-implemented GPS/ SatNav to offer suggestions to get you to your destination -including advance lane advice- is a good thing, definitely when compared to sticking a bit of paper with scribbled notes somewhere. The time to destination and traffic-info adjusted remaining journey time will be reassuring if you left in good time, otherwise pull over* and advise the place you're about to visit how much later you'll be.
When it comes to any conversation I see little difference between my 90-odd year old father trying to drive home some argument which figures large in his mind, anyone on the phone, or my mother grabbing an ear and yanking the driver's head sideways : "Oh, look, those lambs, aren't they wonderful?" ... "Why aren't you looking?"
To which my reply tends to be "because I'm driving (say 120 along a motorway), that's why" - let me add a note here for readers in countries with hand-and-feet measurements: 120 km equals 75 statute miles.
* While clarifying things : please do not hit the brakes in a curve on the sliproad soon as satnav advises you'll be a minute late (not only because you'll be even more late once you made the call) : go find a place designated for at least a short pause, indicate in good time, park safely and considerately; give consideration to what you're about to communicate, make the call / send the text / e-mail, and when circumstances allow re-join traffic in a safe and considerate way.
A word on jamming signals : passengers are not precluded from using their mobile phone and similar devices.
About draconian penalties : people get killed at pedestrian crossings, or while cycling along a clearly marked track along the side of the road, through rear-ending in fog, or loosing control on slippery road surfaces, all of which lead to death and/ or injury, once in a while : would anyone second the proposal of a 100.000 fine and five years in jail for driving under adverse conditions? Just like with mobile phone use while driving : people do get killed as a consequence, be it because they're distracted or unable to see far enough ahead.
On a more sensible level : who'll support murder charges with a mandatory life-sentence for killing a pedestrian on or near a clearly marked pedestrian crossing, or a cyclist on the marked track set aside along the carriageway? What about driving while clearly unable through alcohol, 'recreational' drugs, or 'therapeutic' medication : is there any real difference between the result of the one and the other? How about driving a car with poor tire thread, worn brakes, or restricted visibility through ice on windows or snow sliding off the roof?
May I end with a snippet on fines from the City of Westminster, London, UK ? The on the spot fine for dropping litter was set at GBP10, and the streets were almost litter free; for some reason the fine was increased to a mandatory GBP1000, and actually more litter was dropped because the fine was held to be out of proportion to the cause, thus the wardens turned a blind eye to children and tourists losing the odd sweet wrapper.