^ Yeah, same here. I'm only slightly lactose intolerant, so I guess I'm lucky. I can handle a normal amount of dairy, like milk in a cake... but I cant like sit there and drink a whole glass of milk. Then I'll be miserable.
I'm also allergic to red food coloring, but it doesnt stop me from eating something.

I guess it just depends how allergic someone is to something. But some people are deadly allergic to certain things, so I guess for them eating it would be a big no no.