We live in a representative democracy. (If there's any 'raping of rights' going on it is far more by corporations who have their own perverted ideas of their proportion of representation than it is by our governments.)
Now where do laws and rules come from in a representative democracy? They come from the will of the people. They do not materialize out of no where.
There are laws at all governmental levels on vehicle noise generation. If there weren't I believe most of us would be a lot unhappier. Remember it's about life, liberty, and the pursuit of happiness.
But here's the complicated part. It's not these three things
just for you, it's these three things for
everyone.
Now just because you can get away with loud piping your motorcycle, and just because others are doing the same, it doesn't make what you are doing right. It doesn't make the law any less valid or the will of the people any less clear.
Riding a motorcycle is a personal choice and one you should make in full awareness of substantial additional risks. You can improve your odds by wearing a helmet and bright colored protective clothing, using a headlight modulator, mounting a loud horn, and riding sober and smart (make sure intersections are clear, dont' tailgate, don't pass left-turning vehicles on the right, keep out of driver's blind spots, drive at the right speed for the conditions, go into turns slow and go out fast, etc. etc. etc.). These measures together make a loud pipe not only illegal, but unnecessary.
P.S. I've got to admit this debate is more enjoyable than an Oil War or Seafoam thread.