Well, some colleges do just what you say---teaching writing and study skills to the students who need it. But in my experience, a lot of the students have been

Well, some colleges do just what you say---teaching writing and study skills to the students who need it. But in my experience, a lot of the students have been taught study skills in the past, but it never stuck because they didn't really need them yet... and in those cases getting a bad or mediocre grade really is just the swift kick they need. As for reinventing the wheel, are you suggesting that the professors should try to grab someone else's slides and lectures and teach from them? I promise that this does not work very well. Aside from being drier and less engaging to read someone else's stuff, it means that they aren't tailored to the prof and to the class. And a good chalkboard lecture beats slides any day, anyhow.