We are not talking about all of open source here; there are crucial bits of code and less crucial bits of code. LZ/OpenSSH was obviously in the first category. How do you determine which ones are more critical? same as you would for a bridge or a plane: by risk, impact, etc. That's basically liability.
And obviously a non-insured piece of code that assumes no liability whatsoever can still be free and maintained via IRC, same as it ever was. I dont see how this "kills all open source".
Companies and in fact everyone has the choice to NOT use software that comes without warranty. But, of course, the cost difference will be astronomical. Alternatively companies and everyone have the choice to inspect open source software for security problems BEFORE use. Of course, astronomical cost.
This is an attempt to shift costs onto open source developers. Which, aside from being totally unjust, won't work. There's a legal expression "you can't squeeze blood out of a stone". Shifting costs onto people that can't carry those costs doesn't work for the same reason supporting a skyscraper with a toothpick doesn't work. The toothpick breaks, and when the skyscraper lies collapsed on the floor, nobody blames the toothpick. Hell, they might say the toothpick was heroic: trying to save the situation, sacrificing itself, screaming, and when nobody helped, not the government, not the owners, not ... the building collapsed and all the damage was done.
But it's even more stupid than just that. As soon as this gets introduced, and some company makes a security fix. They of course, for GPL or AGPL software, have to release their fixes. This will then make them liable for any other security problems in that same software. After all, they'll be the last ones releasing that software after the government implemented this law.
So how will you even do this, without making software fixes effectively illegal? Achieving the exact opposite of what such a law tries to achieve ... But of course, you can't have this discussion with people just looking to keep "their" free stuff but trying to shift the rest of the costs.
And obviously a non-insured piece of code that assumes no liability whatsoever can still be free and maintained via IRC, same as it ever was. I dont see how this "kills all open source".