Ah, nut warnings...

I am a very good customer of a local chocolate manufacturing plant. They do wholesale and have a small retail outlet near where I work. They explained that one to me one day...

Nut oils are one of the nastiest allergens (except maybe shellfish) to people allergic to it. Most food allergies will not kill you. This one can - if you are hypersensitive to it. Not very common, but...

Any manufacturing plant that processes nuts in any way must have that warning. The nut oils are so pervasive that they will contaminate the production line they run on. After that, anyone allergic to nuts will have major trouble. Even if there are no nuts in it (like that 100% shredded wheat), the mere traces of nut oils in the equipment can be lethal to that small fraction of the population. They actually have to have a dedicated line for non-nut varieties or carry the disclaimer.

This particular factory chose not to manufacture anything with peanuts in their facility just to avoid having to put a warning label on everything they made.

Not that there is not a lot of stupid labeling (there is) or people out to make a quick buck (there are). But this is actually a life and death issue to some people. Not many, and I am glad I do not have to deal with that one personally... Imagine having to check your box of cornflakes to see if they could kill you...