Where, even in the best, you'll find 1/10th the substance you'll find in the best of books, packaged in vacuous snippets for quick consumption, and written to gather advertising...
The person who wont read any of the classic books (be it science, non-fiction, literature, history, etc.) but will still read magazines and newspapers, I'll still call illiterate - even if the magazine was the Economist or the National Geographic, and not Men's Health and Cosmopolitan (which more often than not, is).