Because audio is easier than video.
Some other really cool music videos (or at least I thought they were cool) just to throw something in therehttp://www.youtube.com/watch?v=0XH3oMNKApI(that band actutally has some pretty cool ones I think. Plus, look at the lead singer, he's just a card. Or maybe even a deck)http://www.youtube.com/watch?v=-QBOJZolP6ohttp://www.youtube.com/watch?v=rEXhAMtbaec(I just can't get over how pretty an image they mad with just... lights and umbrellas and water and random people passing by... and inflateable thing-ma-jigs??)http://www.youtube.com/watch?v=4N3N1MlvVc4I just think the striking thing about videos like these is that, these probably didn't cost more than the cost of the cameras lights and props. Plus, not too much looks like it was done to any of them past simple editing.Random two cents!