The level of noise is not the issue. It seems to have become the American way to complain, that is the issue.
Quieter does prevent the complaining from happening as often.
BUT the ones who complain about the "loud" snowmobiles will always think they are loud .
As for motorcycles, we are going through the same issues of people complaining about the noise.
If you think they can't ban loud vehicles from the roads, you should check your local ordinances. They will impound loud Bikes in some areas.
It is WAY easier to put a law on the books than to take them off. (do not drive a red car in Minnesota)(and if you are in a covered wagon in ND you can shoot indians) as examples of old laws.
"Make a law!" they yell at the representatives and congresspersons. Then, later, when they get affected by some other law (that was created by some other complainer) they complain about the law.
Every law that is made to protect someone's freedom takes freedom from somewhere else, when done properly it works well.
The law in Minnesota reads "For any snowmobile built after April 1 1975, Max 78 decibles at 50 feet on the A scale"