Good post, and I'm a parent of an allergic child who agrees with you.
We could (maybe, in theory) ban the big 8 from schools. Trouble is, the "big 8" are just the most common allergens. What about people like my sister, whose most severe reactions come from things like tomatoes, apples, grapes, and celery? Might not sound so bad until you start reading juice labels and soup labels, btw. A child can potentially be allergic to pretty much anything.
Next, your comment about offices and colleges. Picture this job interview:
Yes, Mr. X, I'd really love to come and work for your company. I know I will be a great addition to your team. Here are my qualifications, my salary and benefits desires, and....oh....by the way...you will need to make certain that your premesis are completely eggmilkdairynutapple...blahblahblah...free. When do I start?
Of course every single person who posted on this thread values the life of a child over a sandwich. Of course they do. Some of those who have disagreed with the idea of banning are people who actually live with this issue. We aren't heartless and unconcerned. We just happen to believe that the best way to deal with the issue is to educate ourselves and our children on how to stay safe and function in the world as it is.
The poster who said she has her daughter (or son? sorry, don't know where it is now) lay out a napkin on the table before unpacking her lunch had a great idea. Another great and very basic idea is simple hygeine. I agree with the poster who asked why there are not a row of sinks in every lunchroom. But even without that, there are sinks in the school. My kids' schools have one in every classroom, plus the restrooms. There is absolutely no reason that the kids shouldn't be washing before and after meals, and no reason they shouldn't wash when they arrive at school. This would cut down on a lot more than food allergy issues; it would cut down on the rampant sharing of germs common to school environments. Yes, it takes a few minutes of teaching time away, a couple of times a day. Compare this to days, weeks (or potentially even lives) lost due to illness and reactions, and it is a very minor loss. I think we would be better served, and more successful, lobbying for basic hygeine measures in our schools rather than food banning.