a movie that Lucas has previously criticised for dwelling too much on its own set design accomplishments rather than drive the story forward
I'm pretty sure it was his idea, on the Episode III commentary Rob Coleman says that Lucas asked for it to be put there as an homage to Kubrick. I'm also sure that he loves 2001. Lucas was interviewed for the new Kubrick collection, and appears on a few of the documentaries in that set. The longest segment with Lucas is on the 2001 documentary, where he explains that he loves 2001 because its a mainly visual film, and that he found it inspiring that someone could make a successful visual film. Lucas says that he probably would not have made Star Wars if Kubrick hadn't made 2001 (or something to that effect).