If I had a vehicule so fast it could literally kill me, I would never drive it around other people knowing my life was potentially in the hands of some inexperienced driver who has not the slightest concern or knowledge regarding traffic laws.
I could find plenty other analogies, but you get the point... So many mundane everyday activities are life threatening in a way, you can't blame people for living...
Asking the waiter for problematic ingredients and insisting on how severe your allergy is more than enough caution taken. The fault is entirely on the restaurant. If a blind person was run over after a nearby pedestrian ensured them that it was safe to cross the street, would you blame the blind person for leaving their house alone?
I know right. Imagine the horror: you are about to eat a tasty platic bag, but you realize it's actually a jellyfish