I don't think that's incorrect though. If there exists a mushroom that tends to be lethal in even small quantities and its usage in recipes is restricted, then

I don't think that's incorrect though. If there exists a mushroom that tends to be lethal in even small quantities and its usage in recipes is restricted, then the fatalities caused by it will go down. You might disagree with the method on deontological grounds, but you can't really deny that it is functioning well on consequentialist grounds.