I disagree the Czechs had a worse defense, even on paper, than say Russia or Finland, and if they had a worse defense, on paper, than say Sweden it wasn't by a significant margin at all. Russia missed Zubov (their best D by a big margin) and their D group was solid but unspectacular. Russia also missed Mogilny and had a bunch of unspectacular depth forwards such as Titov, Zelepukin, Krivokrasov, et cetera. They did however have a strong group of Cs (Fedorov, Zhamnov, Yashin), which they don't really have now with Datsyuk gone, but my point is still that I disagree that the Czechs had a clearly worse roster than most of the other top nations. Canada didn't have a very well built team, they had some key injuries (Kariya) and some players who were just too old and past their expiry date (Gretzky).
Jagr may not have scored loads of points this tournament, because they Czech system didn't let him free roam, but watch the actual game against Canada and you'll see how he's holding them back on their toes and pushing them back with his skating, some of their fairly immobile Ds could barely keep up with the guy on big ice.
I also disagree that the Czechs gained momentum throughout the tournament, they were rock solid from start to finish and just played their formula like they always do.