I see no issue in handing out similar punishments in the digital space. The Internet is a shared medium, everyone who connects to it has a responsibility to not be a nuisance to others.
The main ingredient of crime is intent, whatever you say. A smaller ingredient can be recklessness, but maybe it's the ISPs sending all those millions of empty packets to a single server that should start feeling some heat ?
Yeah, not kill, but participating in a DDoS against a heavily frequented commercial site that makes hundreds of thousands of dollars of revenue a minute, that's still some substantial damage.
In the end it should boil down to the ability of holding the seller of the product with security issues accountable for the damages, and the seller in turn can hold the manufacturer accountable. Maybe that will lead to some substantial change.
It sounds like that hypothetical site has an interest in not going down if a random baby monitor sends traffic their way.
Also, to underline how silly and poorly thought through your idea is, are you aware that there are nearly 200 countries out there, each of them with many people with their own internet connections? Or are you expecting DDoS botnets to be comprised exclusively of devices in your jurisdiction?