I understand what you mean, Jinete. It might be that I haven't been clear though in expressing one thing: the usefulness of helping players remember things their characters would surely remember increases with the decrease, for example, of session frequency. In that case, the cards, I think, could be useful, because they are good representation of the CHARACTER'S memory: while the player's memory is unfortunately cluttered, in some cases, with job, school, family, traffic, political issues that happened in the 7, 14, 30 days since the last session. (Yes, even if they REALLY love the game... ) Of course, if players in a group don't need them... no need to use them!
In any case, cards were just a part of the article. I think focusing just on them distracts from finding what good ideas were in the article besides.
As for the advice on how DMing, I agree that should be the main content of a DM guide. But we have no way, I think, of knowing they are NOT doing it: and I don't think we should start out by thinking "they're doing wrong, because they're not talking about what I think they should be doing." Maybe they're doing it but they haven't told yet... or maybe not. In that case yes, it would be a pity. it wouldn't mean 4th ed is automatically a bad game, but yes it would be a wasted opportunity.
On a totally different note, I also wanted to thank Plane Sailing for what he said.