I guess I'm sorta snobbish on this topic. If a person is allergic to peanuts, then he/she should never be in a position whereby his/her own health if put in jeopardy by the normal operations of an existing organization. Examples?
Kids with peanut allergies should not be allowed to go to public schools. They should be at schools with kids of similar allergies. Why? Because it is unfair to the 90% of the school kids who enjoy peanut butter and jelly sandwiches, and for kvetchy mothers to impose their own child's dietary restrictions on another is selfish and inappropriate.
If I were on that flight, I would have eaten my peanuts irrespective of the FA wishes. It really comes down to a matter of Darwinian philosophy. For many, many years, peanuts were a part of the human diet. Obviously, those allergic to peanuts aren't supposed to survive on a human diet. If these individuals are not capable to putting themselves in a position where they would be SAFE from those who carry on like normal human beings and eat peanuts, they should DIE. Survival of the fittest, my friends. It's one thing to ask the FA to not serve peanuts to that person and to possibly have the seat cleaned of peanut dust. It absolutely inappropriate to ask the entire passenger population not to eat what they may have brought on board because the affected patient is not smart enough to distance himself/herself from such potentially dangerous situations.
Peanut power!