there is a lot of suggestion currently within scientific circles that the increased prevalence in nut allergies has to do with the decreased exposure to nuts hence why the advice to not eat nuts in pregnancy has now been revised.
The anaphylaxis campaign advises against banning of nuts because doing so creates a false sense of security among those with allergies and ensures they potentially do not learn to deal with their allergies - instead they just assume that an environment will be nut-free when this might not be the case.
It's one thing for an airline to stop the sale of actual nuts from their flights, but it's quite another to insist that no passenger carry nuts or even products which contain nuts, as they are almost impossible to avoid.
And there are many other allergies which can be just as damaging and actually much harder to avoid e.g. dairy allergies, where possible you could try to keep an environment allergen free but it's not realistic - unfortunately some of that responsibility of awareness does fall to the sufferer of the allergy.
And if children with allergies aren't taught very early on to manage their allergies they can fall into real issues when they start to head out on their own - to secondary school or university where there is not an allergen free zone.
My ds has a friend who has a nut allergy. When he came to my house he asked if a certain sweet contained nuts and then announced casually that "well, I do have an eppipen if they do," 
he was far more relaxed about it than I was. 
and actually that's the way it should be - often it's more that we wouldn't want to be responsible for someone's allergic reaction, but if the allergic person is aware they themselves can be responsible for managing a lot of the risk...