I didn't know that the Americans invented the English alphabet.
is indeed very much style over substance, but I agree that it's style that works very well. It clearly shows just what the Cardassian mindset truly is - something that has been hinted at over and over up until now. However, if I'm not mistaken, this is the first time it's explicitly thrown in our faces like this.
It's also important that this episode really sets the stage, psychologically speaking, for all future episodes showcasing the Cardassians. For example, their blind obedience to the state shows why they would be so likely to join sides with the Dominion.