My biggest concern with the writing of the young today may be tied directly to their use of computers and/or cell phones to communicate. The short hand they use, I have found, works its way into their "formal" writing, which—in essence—makes it informal.
This is only part of the problem, though. When I began teaching, before computers had entered the mainstream, and before text messaging, I asked myself the exact same question. At the high school, I wondered what teachers in middle school were doing. When I chose to move back down to the middle school, I knew I was covering the curriculum and practicing it, rewarding it, etc. However, there were kids that would learn it and those who would not. And honestly, their apathy may be what pushed them to just "get by." On the other hand, when trying to teach students, covering SO much with regard to "English" or "Language Arts," that you can only beat a dead horse so many times. When you do stop testing them on the same things, over and again? How many times do we reinforce the difference between "it's" and "its," and when do we move on? Even when my students knew they would lose a point for every time they misspelled the same word, it didn't seem to matter. It was easier to lose the point than to learn the material. This brings me back to apathy: it's nearly impossible to overcome a student's disinterest.
This has been my experience, anyway.