In all seriousness, warm (or hot) nuts are to me more a signal of a certain level of service, rather than the temperature of the nuts themselves. When warmed, someone took the time to put them in the oven and heat them up, knowing that a majority of pax appreciate it. Same thing when the FA takes the time to preheat the coffee cups. This same person probably knows that no one will complain if those same nuts are slammed down cold on the tray or if the coffee cup is cold. It is one indication that someone cares about customer service, and I for one appreciate it. Hence, my fixation on the temperature of said nuts.

Now, can we talk about my pet peeve, cookies that are heated and then served with the rest of the meal, meaning they'll be cold again before you get to them?