I commute round the ring of a European capital city every day & the traffic is immense.
In that instance a noisier than standard exhaust helps improves safety quite a lot when filtering through the traffic.
I guess filtering between queuing cars is also considered undesirable by many so maybe a poor reason.
As it happens I have a CE marked Akrapovic on my bike with the original catalyst in place too so it's not me making the noise but there are enough bikes with noisy pipes for me to follow through the gaps.
Has anyone else noticed the trend for noisy truck exhausts by the way?
Those things cause some amazing vibrations when you pass them…