In twenty or thirty years, the Wii will be a classic too. "Classic" is in the eye of the beholder.
Right. One could say classic is something which is not current, or newly released...Or I guess they could say what was released first, or around the time of the first games. I consider classic to be something that was new at one point, but has since been redone by another generation title. All Zelda titles other than say, at this moment, Twilight Princess and Phantom Hourglass, and maybe even Wind Waker, would be considered classic to me. The reason I say, other than Wind Waker, is that it really hasn't been very long since the game was released.
But anyway, back on topic, the Fierce Diety mask isn't nooby in my opinion. I hate the word "noob", in fact, because it is simply a term which refers to someone who is just starting out, and aren't as good as say, people who have been playing the game a good portion of the game's life. We all were noobs at one point, and shouldn't look down upon those who maybe can't beat the game the hardest way possible because they haven't played it enought yet to acquire those skills.
The mask itself, however, is also something that takes much time to gain. If you are willing to put as much time into getting all the masks in the game, just to have it, then by all means it is an advantage, a reward in a sense, rather than something that is "nooby". And its ok if some kid plays the game, who someone has already beat, and uses the mask whenever they fight a boss. You wouldn't expect them to up and wear out Majora the first time they had played that type of game.