This is of course in response to my post filled with cliché.
Being able to quote is a great asset, but it is not the be all end all of intelligent conversations. It helps tremendously though; it is rather pointless to put your exact thoughts into flowery languages when someone has already done so more eloquently. There is no reason to talk about how far we've come on tolerance of African Americans, when a simple "I have a dream" would do.
But by saying what has already been said, you are not advancing the world's literacy. By telling students that quoting is a quintessential part of any piece of writing, you are inhibiting him by setting barriers on what "good writing" is. He will eventually have to choose between getting good grades, or writing freely. In our world today, the grades usually win out, and the student strays from his creative capabilities, and "I don't know if I can respect somebody that can walk away from a gift like that."