I was recently on a flight where a fellow passenger was yelling at the flight attendant because there were not "enough" vegan snack options. Apparently he did not fancy fruit.
What is insanely interesting? You can request vegan meals, but there is no option for "allergen free" meals. I have a severe fish allergy and some airlines make it a big more challenging then others.
I can not see Japan Airlines not serving fish, because I am on board. If I get a bit a juice, my throat will close. I still fly JAL, because sometime they fit best with my schedule/budget. After my first mishap have not eating on a 9 hour flight, I've learned to take care of myself.

That being said, I have no issue with not eating nuts on a flight. BUT there is no way, I trust 150 other strangers to not eat nuts to protect me from getting sick. I wouldn't doubt some jerk doing it just to prove a point.
Allergies are no joke, but one should take their own precautions and not trust others to do it for them.