Restating or paraphrasing a widely accepted thesis statement isn't very educational? When your freshman class of 200 students is writing essays on a handful of topics, the same ones every year, that every other school touches on, there's not going to much in the way of originality.
Then again I guess the same argument can be made for maths but no one complains that we're teaching to memorize and repeat the same steps of various proofs one learns in 1st year.
