Only purpose of this bit of kit is to create noise and annoyance. Most vehicles with these are driven by young folk – "Empty vessels make the most noise" comes to mind. No-one with a bit of sense and a decent vehicle would have this on a car/bike.
I would like some peace and quiet at night and during the weekend when these types of vehicles seem to be prevalent. Also people who work shifts and try to sleep have to contend with the noise during the day.