Originally Posted by cvskates

I think you're making an inference where none was intended. The OP said he doesn't understand why someone wouldn't have a sound signalling device given the relative cost. He gives an example of where it's useful, but it's just one example. I use my horn occasionally, even if I'm not passing on the right or lane splitting. I would think have a sound signal would be a really practical asset when practicing this defensive riding you speak of.