the risk is born by the rider instead of the public.

This is some bullshit. A motorcycle may be smaller than a car comparatively but one being hurled at you at highway speeds is still lethal. Both pedestrians and people in cars die to speeding motorcycles every day.

The risk is bourne by the public in three ways:

1. The public pays for the cost of their injuries, either directly through a state healthcare system or in the form of increased premiums. An insurance company has no way to differentiate reckless motorcyclists who are lucky from responsible motorcyclists.
2. A crash on a road will close one or more lanes while emergency services attend the site of the crash, causing congestion. While the overall inconvenience per motorist is small, it happens to many hundreds to thousands of motorists and thus collectively wastes hundreds of hours of people's time.
3. Normalising reckless behaviour increases its social acceptability, and I think that as soon as it becomes widely known that you won't go to jail for operating a motorcycle at double the speed limit, the first people to try this will be teenagers

I ride my motorcycle everyday and ride strictly to the letter of traffic law. The safest way to ride is to be predictable. With that said, I am not wholly in disagreement with you, in that obviously risk levels for others are less than a rider in any circumstance on the road, even ones where it is the motorcyclist travelling with excess speed. That does not mean that consequences for an accident due to the unpredictablity of someone speeding are not shared with society. The trauma of witnessing a lethal accident and traffic delays due to cleanup have different severities but each can have lasting impacts on people. Riding and travelling on roadways in general already are filled with hazards and risks. Anecdotally, it seems as technology in cars meant to keep people safer makes gains in the industry, what it actually accomplishes is that it allows people to be less involved in driving, or even just complacent to not pay as much attention. This is not the rider's fault, but adding the element of excess speed is a recipe for disaster. Ride and drive predictably. I rarely see accidents that are ambiguous. An all too common thread between accidents is excess speed.