And from The Elements of Clunk at The Chronicle:
Standard written English is a whole other language from its spoken (and texted) counterpart, with conventions not just of punctuation but also of many shortcuts to meaning—streamlined words and phrases, ellipses (omitted word or words), idioms, figures of speech—that have developed over many years. You learn them by reading. And if you haven't read much, when you set pen to paper yourself, you take things more slowly and apply a literal-minded logic, as you would in finding your way through a dark house.
Here's what's happening, as I see it. My students aren't unique but represent a portion of the millennial generation: at least moderately intelligent, reasonably well-educated young people. When they write in a formal setting—for a class assignment or for publication in a blog or a magazine—they almost always favor length over brevity, ornateness over simplicity, literalness over figuration. The reasons, I hypothesize, are a combination: the wandering-the-house-in-the-dark factor, hypercorrection brought on by chronic uncertainty, and the truth that once people start talking or writing, they like to do so as long as they can, even if the extra airtime comes from saying "myself" instead of "I."