There’s no way on Earth (ha) that ALL of these planets are devoid of intelligent life, Krauthammer blather and Fermi Paradox aside. The reason we haven’t been contacted is simple: no technology exists to allow for faster-than-light travel, and the vast distances involved mean even if another species developed mechanisms for transmitting radio signals before we did, they’d be so weak by the time they reach us we can’t detect them.

_{Too bad, though - I was really hoping I’d live long enough to see discovery of exoplanetary life and the resulting cranial explosions amongst religious fundamentalists :P}