Well, I belong to both camps. For many years, all I did was ride around on my Harleys. And yes, full-on, ear splitting, custom bikes. It's great fun. It's a whole different kind of high. But, as with anything, 99% of the people are posers, and can be irritating. I love the sound of a good running, finely tuned, muscle bike, loud or not. I can't stand the sound of a posers bike, which is typically a relatively stock motor, with a pair of wide open pipes, just to be loud. It may sound great to them, because it's loud, but it's just an irritating hollow BLATTING to anyone else. A bike that has been modified by someone who knows what they are doing, and has been modified to increase performance and power, and is running well, has a whole different sound. It sounds deep and powerful, and shouldn't offend anyone.
And of course, gear makes an excellent point. God knows that the bicycle culture has it's posers. Gotta be tolerant.