Opening the door gets you Forgotten Cellar, a five-mana Room that is effectively a Yawgmoths Will, letting you cast spells from your graveyard for just one turn
This thing is great in Pingers, Tappers, Aggro, Mana Dorks, Tempo to untap your land in a Winter Orb, or in many other places
And while I'll attest that they do similar things as a true fetch land (and in the case of Maze's End, even provide a win condition), they still often aren't comparable to the strengths of true fetch lands
Since youre making that many Faerie Rogue tokens with flying, you can pump the tokens with rogue lords like Anowon, the Ruin Thief and Soaring Thought-Thief or cards like Gravitational Shift
Even if they are not, there's no assurance you're going to draw more than one a game unless you're playing with Intuition
Untimely Malfunction may prevent a game loss by redirecting abilities from Mindslaver or Flamewave Invoker