Every law written can be abused. That doesn't mean we shouldn't have laws. And of all the differences people have, most people agree with the laws that protect people from intentional and indiscriminate harm.

People with loud exhausts are injuring people intentionally and indiscriminately.

Usually it's through a stress response that turns into PTSD if a person has to endure it for too long.

Another injury comes from sleep deprivation. Going days/weeks/months/years without reliable and uninterrupted sleep is an actual torture method that permanently damages people in both mind and body.

Other times it's tinnitus from being exposed to noise levels far, far above safe ranges. Even "quiet" bikes are allowed to be well above safe noise levels. Tinnitus doesn't heal.

Hiding behind your freedom of expression to justify intentionally and indiscriminately injuring people is low.