The poll ranks exposure as much as anything. It would have been surprising if, say, Sufjan Stevens got the top spot. Green Day? Not so much. Everyone heard something off American Idiot. It was an insanely radio-friendly album.
------ Here are the highest-reviewed albums of the decade, according to Metacritic. Looks like critics and the general public can't agree on anything. I'm going to have to make my own list, just for fun.
I couldn't name one song on any of those albums except Green Day's American Idiot, and I'm not a Green Day fan. I think this goes towards the amount of radio play that album got over the decade, and there was TONS of it.
GREEN DAY GARGLES MY BALLS! I think Clapton/Winwood shoulda gotten best album for their live at Madison Square Garden wins......... Me and Mr Johnson was great too. Even Back in Black was better than that shit.