Your approach is unpractical and I doubt you follow it yourself. Almost nobody that uses opensource libraries reads all of the code. As with journalism, science and many other things in life, you have to trust upon others to deliver work that conforms to certain standards. Even though every newspaper article and scientific paper that you accept is 'your responsibility', you would be pretty miffed if an article in the free local paper was completely false.

If you give away toilets for free, it's your responsibility to make sure they aren't lined with sodium and will blow up after the first flush. If you give away a toilet for free, you are an asshole if you know it has a huge hidden hole and you don't warn takers about it. If you write a piece of software that claims to be doing something, but it actually contains malware, then you are violating the law (as much as when you give me a nice statue that contains a spy camera).

It has never been possible or allowed to give just anything you want away for free, without you being liable in any way. That hasn't changed with software and no license in the world can exempt you from certain basic responsibilities concerning your 'gift'.

Are you speaking morally? From my understanding the warranty disclaimer in many licenses (GPL, BSD, MIT) does exempt you from responsibility...

Claiming you are exempt from any responsibility does not actually legally exempt you from any responsibility. You can't legally bring a spy camera into my home by presenting me with a free gift that contains a hidden camera. You can't legally blow up my home, even if I accept a free device from you and press the buttons you told me to press, unless you were very clear about what the device would do (and no, claiming in the license that it is not meant for anything does not nullify the website and the examples of what the code is obviously supposed to do). Going from the realm of the obvious to the realm of the somewhat less obvious: if you give me a free bicycle, knowing it's fron fork is starting to give way, you are responsible for my skull fracture if you don't tell me about it. The practical problem, usually insurmountable, is proving you knew about it. More broadly: the consequences of known defects that obviously have disastrous consequences are the responsibility of the provider. This also holds for software and doesn't depend on the license.

Now my point is not that this is the case here or that such cases are common or even important. The point is that the blanket statement of my parent is plainly false.

Of course, IANAL, but you don't need to be a lawyer to understand jurisprudence. There are plenty of known cases where people intentionally harmed others and tried to plead guilty based on not actually performing the action that lead to the damage. It doesn't fly.