Yeah, they should, but if someone with that severe an allergy is on the plane, would that be allowed? Also people are stupid and don't think ahead or plan for contingencies: I can see people reading there will be food service and deciding they don't need to bring their own.

It's not always only ingested food that is a safety issue. Some people have allergies that are severe enough that physical contact is enough to cause anaphylaxis. For example, there was a kid with a dairy allergy who died when other kids put a piece of cheese down his shirt[1]

[1]https://www.theguardian.com/uk-news/2019/may/02/boy-with-all...

I did. I was told I could not eat it due to the possibility it contained nuts.

Both of these flights were TATL but on the lower end (5-7 hours) of the time range. The restriction only applied to our section of business class, which neither time was fully booked.

"If being exposed to trace amounts of [an allergen] on a flight is a medical issue, someone shouldn't be taking a plane."

You mean, forced to buy food at 500% markup inside the airport.