Tetris is a game that lasts because it is a geometry puzzle. It's highly stimulating, and while the the pieces handed to the player are random, their placement and effect is always player-controlled.
(Meanwhile, Angry Birds is a game with very random outcomes, where you'll only be able to roughly calculate the effects of your actions, and you're likely to find yourself repeatedly restarting a level in order to get the semi-random outcome you wish for.)
Tetris is a game about shapes made of four colored blocks, like a T or a box, that come down like falling bricks. You can place them in rows, but everybody knows that they made this game for chi-- err...
*plays some more Tetris*