alt Hacker NewsI dunno, usually they seem to have good enough. I'm not sure what the risk is for "faster walkers approaching from behind" but where I live, it's the etiquette that it's the responsibility of the one passing to make sure to not bother the passee, it's not up to them to make sure you don't walk into them. The other points just seem over the top cautious as well, but maybe I'm too European to understand the constant stress and threats that seems typical in the US and similar places.
I'm fairly sure people are aware about the fact that they're missing a whole sense + some situational awareness when they're wearing headphones and walk around :)
I'm in downtown Toronto, and there are plenty of (very quiet) electric cars, all sorts of quiet e-bikes and other electric personal transportation devices (scooters, e-unicycles) and other things (roller blades, bikes, skateboards) where often the only sound is the noise of the wheels on the sidewalk / pavement making a quiet hiss / rumble. I do a lot of walking, and headphone people are often (but not always) quite clueless about these things approaching. Granted, those other people aren't supposed to be where people are walking, but they regularly are, sadly.
Passing isn't something that is only the responsibility of the passer, that of course is absurd. Most people don't walk on the very edge of a path, but slightly off from the center (or in the shade close to the buildings if hot, or far from the street if puddles and raining, and etc), and you may also be carrying things that make you take up a lot of space.
So, in practice, as a walker, you do in fact have to be aware of people approaching from behind, at least, if you aren't an ass, because it is often kind (or even necessary) to move aside a bit to make passing easier / possible. Earphone people are some of the biggest assholes in these scenarios.
EDIT: But I fully agree that once you get out of the chaos of the downtown core, or likely plenty of other cities, this is probably just not really a meaningful problem / tradeoff.