And justice is finding 9 or more people and executing them?
It's clear you don't care about justice or you'd be looking for the people responsible and punishing them based on how much culpability they have, personally.
What you're describing is eye-for-an-eye vengeance.
The harm was much greater than nine deaths, many other people were poisoned. Someone is responsible. They won't be held responsible under our current regulatory and liability framework.
If you want this kind of malfeasance to stop, that framework needs to be changed. There's a fundamental disconnect between decision-makers and beneficiaries of this harm, and the responsibility that they get to shirk.
Consider that tampering with food (for no personal gain) that doesn't seriously harm anyone carries sentences of multiple years. Scale this proportionately.
It's clear you don't care about justice or you'd be looking for the people responsible and punishing them based on how much culpability they have, personally.
What you're describing is eye-for-an-eye vengeance.