I know that "mature" was never a word in my post.

I have already said that we have no problem with food restrictions. None.
Now as to peanut free classrooms. No peanut products in the classroom is how DGD's school handles it. All lunches are left outside the room and no snacks that contain peanut allowed in the room. There is a table "for a few years DGD referred to that table as the "peanuts" and many days had lunch there with her friends. SO far there have been no allefgic reactions with any kid in DGD classes.
Now we get to that "mature" thing.

DH has a cousin and his wife who is, let us say, mean, uneducated, immature, selfish and self-absorbed. WE took them out to dinner and my DD and DGD accompanied us. DD seldom drinks, she is a bit of a control freak and likes to drive. She will not drive if she has had one drop of alcohol.
Anyway, we had been dealing with Kady's allergy for a few years and were beyond impressed with how the school, the teachers and the kids were treating it. DGD had gotten used to discussing how one friend or another needed special food for a party so it was clear all the kids were respectful and compassionate of each other. Cousin's DD tells us she has a kid in class who has a peanut allergy so if they want PB they need to eat it in the hall and expresses of unfair that is. "Let the kid eat in the hall!" DH goes still. So I tell her that the child has no choice about her food but her classmates do. They can choose to eat alone if they want PB but the little girl should not be forced to have her snack and lunch all alone. Mom gets all huffy and tells us she "refuses" to deal with any kids allergy.

Bet she is a peach at PTO meetings

DD, who has already had one mojito kicksm me under the table and hails the waitress so she can inhale another cocktail

DH is shocked. How could one person jeopardize a kid for a PB&J sandwich?????
But it happens. And it will continue to happen. You cannot inform people who do not want to be informed. But the answer is not in the blanket bannings of peanut products that some school systems have resorted to. Thank goodness DGD school system has been able to gain cooperation from most of the parents in the school population. You restrict only what needs to be restricted when it is appropriate. Most folks are okay with that. Unless those folks are my DH cousin