Inevitably, when a bicyclist death by a car is in the news, asshole comments will try to figure out why the bicyclist is at fault. And maybe the bicyclist was acting stupidly. Maybe they were riding poorly, making themselves tough to see, etc. But the thing those comments miss is that drivers have a responsibility not to kill people.
And it’s not just cars and bikes. Anyone that’s a step up on size and safety has a special obligation not to hit something that’s a step down. I have friends who ride their motorcycles pretty dangerously. They ride ridiculously above the speed limit and ride between the lanes. They sometimes don’t wear helmets. Stupid, stupid; don’t do that. Still, if you’re a driver, have the wherewithal to not hit one, for Christ sake. Be aware of motorcycles long before they get to you, and check your fucking blind spots. Even if a motorcycle was driving poorly, if you want to be on the road, be a good enough driver that you don’t hit one.
Motorcycles and cars similarly have an obligation to be extra careful of bikes. Ideally, they’ll wear bright colors, have lights, and drive defensively. But even if they’re ninja riding the wrong way, you should be able to avoid them. Slow goddamn down, and chill the fuck out when you’re near one. If you hit one, after all, there’s a good chance they’ll die. And they aren’t even coming particularly fast.
And finally, cars, motorcycles, and bicycles have an obligation to avoid hitting pedestrians. While a car-pedestrian collision is more likely fatal than a bike-pedestrian one, in both cases, the driver and the bicyclist are moving faster than the pedestrian and will hit them with a hunk of metal. If you can’t avoid hitting a pedestrian, even one who’s jaywalking poorly. Even one obsessed with their phone, and not paying attention at all.
None of this is to say that motorcycles, bikes, and pedestrians shouldn’t look out for their safety, of course. Only that we’re sharing the space, and the larger modes have an obligation to the safety of the rest of the road.