Ever seen a head on collision at 30 mph?
A few years ago, I was at an auto crash test facility and stood about 20 feet away from a 25 mph test collision.
Violent doesn’t even begin to describe it. We analyzed the slow motion video’s after that.
Putting a bunch of extra safety stuff like soft bumpers onto a car for even a 25 or 30 mph crash is pretty much a placebo.
Yes, of course in those circumstances what’s on the surface of a vehicle isn’t going change the outcome. But a high proportion of car/pedestrian collisions on UK city streets are at low speed - 20mph or less, when ‘soft’ surfacing can significantly affect the severity of any injury.
(By the way, this has nothing whatever to do with the ‘nanny state’. It’s a matter of law, and British law on the interactions between road users derives from the basic Common Law principle of ‘duty of care’, which was established long before a ‘nanny state’ was ever dreamed of!).