Stock, they’re not supposed to be that loud per regulation. Even Harley’s,a brand I particularly dislike. Modern bikes have a computer-controlled valve before the muffler to attenuate noise for bikes over a certain power. This way big engines can be quiet when rolling around neighborhoods, but give you full power when you’re on the track.
That people go wot on the highway, I also am not the biggest fan, but humans who like bikes, like going fast