Why is noob not considered an insult, but id**t is?

This is a question that has been bugging me for several Tanki weeks. Here is how the story starts: I play Tanki Online, and someone calls me a noob. I get offended and report to the Moderators, but they say that noob is not an insult. On the other day, I wanted to call someone idiot because they did not know how to insert link, so I typed idiot and pressed enter, and this happened (This is just a test image. If you see the first text on below left, it says noob, which does not have asterisks but the next text is idiot and it has asterisks) :

Both of them are offending, but why isn't 'noob' considered a slang!? Sorry if this question is offending, but it isn't fare that noob won't be an insult