No, they don't.
Kids motocrossers are rarely used to their full potential outside of pukka racetracks and could easily be fitted with quieter endcans. Some of them already do but there are so many cheap chinese bikes coming in these days with no parts or accessory support.
Then there are other types of dirtbike. Trials and trailbikes are what most kids used to ride before factories started making pocket scramblers, only one of my friends had a motocross bike and it was offensively loud even to rest of us.
Although I'm sorry I stuck up for them then the whole thing got ugly I do hope there is still room for kids on bikes in the world.
We didn't have to cut a track as there were already tractor tracks for most of it, our relationship with the farmer was great to the extent of buzzing back through the fields ahead of him opening and closing gates, none of us had fire fetishes...
...just somewhere to ride around.
