It's no nonsense, it's common sense. What's the point in making a thread which already has been made? It's way more annoying to see people making the same threads over and over again because they refuse to use the search button (or just their common sense), somehow thinking that they are the first person to make a thread about something that already has been chewed over hundreds of times, than the people who say that you should use the search button.
Mainly the person who made the thread could find that comment possibly annoying, however a large part of the people who read the thread are annoyed by just the existence of the thread and the refusal of the maker to use the search button.
You could possibly only know that if you used the search button, but based on your behavior in this entire thread you refuse to do that, so how could you possibly know that? If someone actually said that you should have used the search button, it's implied that the thread has possible at least once, or more, made before. So saying that they're unique is a complete baseless statement. Unless of course you would have used the search button to confirm it, which would make your entire statement void as then using the search button is indeed quite useful.