I was under the impression that he said that because he didn't have a book reading application yet and was downplaying the kindle until the iPad was out. Similar to how he downplayed the netbooks until the iPad came out. (Yes iPad and the netbooks are different but they are in the same field. I think it's harder to reinvent books compared to small portable computers. Hence why iBook is pretty much the same as all the ebook software).
I think looking at something (netbooks), then turning around and selling 3 million units of a vastly more expensive and higher margin product in a few months, shows that he was right to downplay it and that the iPad does actually offer something fundamentally different that consumers really want.
