Y'know, I'll just say it out loud: these lists do matter, and this one is about as authoritative as it gets. Sometimes you don't want to be all inclusive and diplomatic and diverse in your tastes; sometimes you want to be ruthless, and rate one work superior to the other. It's human nature; more, it's fun, like scratching an itchy old scab--you can't help it, and you sneak a quick rub even when you don't mean to.
It's also a way of charting trends and fashion, and one trend the list does chart was the enduring reputation of Welles' debut film, which lorded it over this list (and almost every other list) for some fifty years. One might also note the relative domination of American films (four on this list), the relative lack of presence of Asian films except Japan (which is allotted a measly single slot), and short shrift given to comedy (Renoir's Rules of the Game being the only if formidable finalist).
For the record, I do like the choices on the list, especially the new number one; have long maintained that Citizen Kane while a great film is hardly Welles' best work; think that Sunrise is a great film too, but that Frank Borzage's Seventh Heaven is far more affecting (and consider Murnau's Faust to be his masterpiece anyway); bemoan the lack of Bresson or any film from Indian cinema (easily the most prolific in the world) on the top ten; love Tokyo Story but would rather put Leo McCarey's Make Way For Tomorrow in its place (and anyway have a different pick for favorite Ozu), and scratch my head at the near-absence of any woman filmmaker (to be fair, I couldn't bring myself to include one either, an oversight that needs to be corrected this millennium).
Far more interesting for me--and again, I'm hardly saying anything new for me--are the individual lists, that show the tastes of hundreds of filmmakers and critics. Those I'll be poring over, once made available (the website seems to be down as of this writing, and I'll take that as a hopeful sign of interest), and noting down unusual choices, and unknown titles. That's the exercise's real resource--an excuse to watch more films, hopefully find new gems, new masterpieces.
And finally the value of this list is to show the limitation of all aggregate lists--that they're the result of compromise and groupthink, rather than an objective reference. So once you've read it, definitely disagree and draw up one of your own. As Mao once said (minus the sinister ulterior motive): "Let a hundred flowers bloom."