I'm pretty sure that fining someone that risks their life is as illogical as I have ever seen an argument. If someone chooses to "drive recklessly" (or I guess in a way where they increase their risk of serious injury through behavior), then a monetary fine will not change that decision. The only thing a law does is increase the number of criminals. It won't deter anyone. It's ineffective. Let them learn their lesson. If they hit a wall, well, they hit a wall. It's a win win. If they make it, well some day, they will be your age and look back and realize how risky of a decision that was.
You are taking someone who has not committed a violent crime, and are initiating violence against them in order to make them pay you. That is the bottom line. It does not change behavior, it does not help them, it does not help you. It helps the government entity that is holding the gun to their head and forcing them to pay.
Two guys on motorcycles, speeding, are not a risk to anyone but themselves. You can't arrest someone because they might kill someone else. They have to first hurt somebody before you can take away their rights. Besides, speed limits are generally set too low, and the laws that govern the roads don't necessarily reflect safety.