Why are pocket bikes, Dirt bikes, ATV's, and lawnmowers so loud?

I don't get it why are they so loud especially pocket bikes. Why can't they make them quieter so people won't have to restrict them because of their noise level. Why are cars quiet and most motorcycles quiet. How come these things can't be quiet so we can enjoy them and, not be caught by the cops?Why are pocket bikes, Dirt bikes, ATV's, and lawnmowers so loud?
Road legal vehicles and outdoor equipment have different requirements and allowed levels.
Mostly because they are two-cycle engines. Tuning the exhaust is crucial to the performance, thus they wont run well if muffled completely.Why are pocket bikes, Dirt bikes, ATV's, and lawnmowers so loud?
all of these vehicles are not under the guidelines of the anti-noise ordinance legislation
You forget snowmobiles.... Same reason most are getting banned because they are 2 stroke.Why are pocket bikes, Dirt bikes, ATV's, and lawnmowers so loud?
the exhaust pipe they need to be bigger.

california academy of sciences