The whole point of reminding readers about CinC is so they don't just stop questioning. In Slate's example, the study found that depressed men use e-mail more. That is correlation. The cause may be that these men have more free alone time, which could cause depression and allow them to e-mail more. Or perhaps they all eat carrots regularly which hitherto no one knew caused both depression and increased e-mail usage. You can't know until you experiment over and over again and have your results verified by others.
The problem is asinine science reporters taking a rather innocuous claim from researchers and spinning it into a huge, black-and-white, cause-and-effect, specious argument like e-mail causes depression, Facebook makes you fat, or toasters prevent pregnancy in Taiwan. Those kinds of articles do not further science and only cloud knowledge more.
But, by all means, Slate, attack the internet commenter instead of a long and sad tradition of misleading, sensationalist scientific journalism.