Big difference between a person feeling guilty about something, and someone else accusing him of murder. I know that if peanut residue on my dd's hand caused an allergic reaction which resulted in the death of another child, I would feel horribly guilty about it, whether or not I knew the child was allergic. It would probably affect me for the rest of my life, just as it would if a child dashed out in front of my car and I was unable to brake in time to prevent my car from killing him. This does not equate to taking the blame, or to a murder accusation.
As for "starving" without peanut butter, I know it's not meant that your child would literally starve. Obviously, if pb didn't exist or if your child was allergic to it, he/she would find alternate foods. But I can see how tiring it would get from the point of view of peanut allergic parents, (face it, it
always gets said in any peanut allergy discussion), when it most certainly isn't true. Someone said their family was vegetarian, right? Wouldn't it cause you to roll your eyes if a friend of your childs came to spend the night and her parents said she had to eat bacon (real bacon, not that soy stuff) for dinner and breakfast, it's all she'll eat and she'll starve if you don't serve it to her? If it does, then multiply that feeling by about 1,000(??) and maybe that's how a peanut allergic parent might feel hearing the "starve" comment again and again. If not, well, you're a better mom than I

I just can't stand such exaggerations.
Oh, and as to the school's request in the OP, I do think it's a little over the top, but it was just a request, not a order. It would have been better to include the request that "if you must have pb in the morning, please make sure your child washes well afterward." I'm sure the child's parents know that not everyone will comply with the request and they will still teach him to be diligent. Reducing exposure is still helpful, though. Just because the risk will never be completely eliminated is no reason to say that schools shouldn't try to reduce it, IMO. That's like saying the nation's highways shouldn't have speed limits because some people will speed anyway.