This whole argument is stupid. It's not the hammer, baseball bat, knife, gun, ... manufacturer's responsibility if you use their product to produce inappropriate results. It's their responsibility to make sure that it can be used safely for it's intended purpose, but not guard against every possible misuse the average idiot can come up with. Is it irresponsible of the manufacturer that I can swing my hammer at my toe? Should all hammers be built so that they will only swing when the target is an approved force receptacle?
if there is a pedestrian on the bridge, is he responsible for his own death? after all it is well known that people get hit by cars when they decide to walk near the road
If it was a "simple" accident through no egregious fault of the driver, manufacturer of the car, engineer that designed the bridge, builder of the bridge, or the pedestrian, then yes shit happens and it sucks. Life isn't pretty and bad things happen all the time.
If, however, there is demonstrable fault on any of the related parties (maybe the pedestrian was naked and distracted the driver...) then the offending parties should be held accountable.
What this means in terms of TFA is that if an engineer inputs bad/incomplete data to a CAD system and the result is a bridge that is not suited for the location that it is actually being built for, then the fault is with the person using the program and not that of the developer. If, on the other hand, the user inputs all the data and it is all correct but the program outputs a bad design, then the software maker has some responsibility (though the users have a responsibility to check the output too).
if the car has a speedometer that goes to 140 mph, can the driver assume that the car can be driven at that speed?
When there are contradicting variables (speed limit, driver skill, weather, visibility, etc..), no and it's the driver's responsibility if they do so.
If you want to take it to a safe location (track) to try to do that, then more power to you and it's mostly on your own head.
Porsche isn't responsible for someone taking their 991 GT3 out to the track, misjudging their apex, and running into the wall. They are, however, responsible for a design flaw that caused some engines to catch fire while being appropriately operated in normal driving conditions.
if the owner of a car knows full well that their ignition switch is acting strange and they keep driving the car anyway, are they responsible for the resulting deaths?
If you know something is dangerous and do not take measures to address it (fixing it yourself, not driving it, etc..), then yes you are 100% responsible for your actions and the results. I know the engine in one of my cars has a couple of design flaws that can lead to a catastrophic engine failure in a measurable percentage of cars. I also know that the manufacturer failed to acknowledge the issue and address it. I am also aware that there are now after market solutions that address most of these problems. Finally I am also aware that it is fully on my head that I continue to drive the car with the risk of losing my engine because I currently opt not to proactively address the items at this time.
The problem with this particular argument which you fail to grasp is that while GM knew of the problem for a long time, they made light of it at best (telling people not to use a keychain) and actively hid it at worst (never issuing a recall or warning to owners, you only got the keychain response IF it had failed and you complained). I also believe that even in those cases where people experienced the failure and got the keychain BS, they weren't informed that their airbag was being disabled at the same time. If that is indeed the case, then GM is doubly responsible as it not only told them not using a keychain solved the problem, but it also implied that the vehicle was otherwise safe and operating as expected (the average person does not understand that the airbag is tied to the ignition).