His reply was to you not thinking being stopped at a red light, with your car running, and foot on your brake pedal (the only thing stopping your car from going forward) can be affected by being "distracted" or the possibility of being distracted when at a stand still.
I will give you a couple of examples which "distraction" at a red light or stand still can be "dangerous". You may question the chances of these things happen, but they COULD an they HAVE. And like I said before, laws are placed to prevent incidents that could and have happened.
-you are reading your Ipad at a red light... you obviously are not focused on anything else but the screen of your electronic device. The light turns green you take your eyes off the ipad, take your foot off the brake, and hit the gas. OOPS didn't see that pedestrian running across trying to beat the light... OR didn't see the car that just tried to beat its red light. BOOM. In those two incidents, was it your "fault". Probably not since you had the green light, but if you weren't "distracted", you would have seen the incidents unfolding before you.
It is the duty of all drivers on the road to be aware of their environment and surroundings. Everyone learned about defensive driving when they got their licences. No one ever gets behind the wheel and thinks they are going to get into an accident. No one ever texts and drives thinking THEY will get into an accident. No one ever drinks and drives and thinks THEY will get into an accident. Because they are "better" than everyone else and nothing can happen to THEM.
There is a reason why impaired driving and electronic device laws were created. Because it is an issue.
Not even going to bother replying to Sebberry. I think I have said that before?
I will let the local Police on the Island put up with him.