I didn't think this was terrible. Some advice was spot on, some I disagreed with, but it didn't seem awful.
It seemed more based on reality than the way things should be. So no, brides and grooms shouldn't ask for cash or be upset if they get gifts off the registry. But if you're not a regular wedding-attender and you're trying to figure out what kind of gift to get, it's really not bad advice at all to give gifts from the registry or cash. No, that's certainly not required under etiquette rules, but you're more likely to end up with a gift the head couple likes. Etc.