Evaluation of an Essay

Being in a writing class, there is a lot of speculation that surrounds writing. When a paper is written what determines the grade that should be recieved. Which brings me to the question of : what makes an average paper into a great paper? Well there are things that I feel are given... A paper must follow the form given, whether it's a persuasive essay, argument, or eulogy remembering someone. It must follow the form for the desired type of essay. Another requirement that must be met is your paper must be gramatically correct. That means no mispelled words, right punctuation, commas, and a good use of vocabulary. The argument exists in the topic of the paper. Just as an artist would create a picture of his or her vision of an object with a different spin upon it or a sort of pablo picasso picture. A paper is very similar because the view of the paper depends on the view given to it by the author. The paper is the authors canvas, words are used like paint, and the final draft is the masterpiece. How is it a teacher can give a D to a paper just because they simple disagree with the topic? I don't feel it's right, as long as facts present the paper that it is portrayed then the grammar and fundamentals should be all that is graded. The opinion of a paper is solely up to the author whether it is in line with the teachers view or against it. Papers are the outlook of authors as artist create their view of the mona lisa, the paper describes it and all the intangibles of it. Does anyone disagree with my statement? Being that we are in a writing class, this could cause stir between teacher and students.