Regardless of whether tooting the horn behind a cyclist is a dick move or not, what’s the cyclist meant to do upon hearing it? If the answer is nothing, which it should be, then what’s the point of it? I only need alerting if you’re about to plough into me, and even then, there’s probably nothing I can do about it.
It’s the same conversation about riding with headphones, what exactly am I missing out in riding on the road with headphones?