The point is that they are trying to avoid ER visits by listing the ingredients that are in the dish and/or in the kitchen. Jay G says it better than I could:
"Look, if you have a food allergy so severe that mere contamination from preparation will pose a life-threatening risk, it is incumbent on YOU to be informed about the culinary practices of any restaurant you visit. If you are so susceptible to allergens and do not perform due diligence in checking out that your food is not properly prepared to avoid a reaction, then I'm sorry but you've earned the ride in the back of the ambulance."
One of the adverse developments to my wife's illness is some pretty nasty food allergies. The smell of Guacamole causes her throat to swell; touching bananas causes instant irritation, swelling, and redness. These are just two of many examples. My daughter is allergic to fish, so allergic that she had a reaction simply visiting the Long Beach Aquarium (btw, great place, go if you can). This precludes me from two awesome things while out to eat with the family, fish and fajitas. Seriously, fajitas with the itty-bitty shrimp, chicken, steak, a good spanish rice and fresh guacamole-pure heaven.
A simple word to the server is generally all it takes. Do I think that the government should force restaurants to list all this stuff? Nope. Do I think that the restaurant is responsible if my wife passes out on the floor because I ordered a steak burrito with extra guac? Nope.
People, we all have to be aware of our situations and deal with them accordingly. Government interference or forced compliance is no substitute for what should be your responsibility. You know what you can do and what you can't.