As for the hot coffee issue: It's one thing to expect the coffee to be hot, it's another to expect it to be scalding (over 125 degrees F, 52 C).

When I was about 12, I think, I was visiting with a cousin, and she handed me some hot cocoa in an insulated mug. Because the mug was insulated, I had no idea how hot the cocoa was (she might as well have handed me a luke-warm drink). When I took a sip, I scalded my tongue, jumped, and spilled the cocoa in my lap. I had a good sized blister burn (felt bigger than it probably was) that took a couple weeks to heal...

Wouldn't wish that pain on even the thickest idiot. Though I agree: the warning would make a lot of sense if it said: Warning: Contents may scald!