New Writing Construct ?

My new proposal for a writing construct is when teachers give students page requirements. I find it a bit irritating and irrational. The idea of making students write "a minimum of 4 pages" or so on is useless. Most of the time students are forced to just lengthen and ramble on in their papers, in which teachers will complain how the student goes "off topic". But if there wasn't a page requirement- there would be no rambling. I believe that students should have the choice to stop writing when they feel their work has meets the requirement of the assignment. Matter of fact what does word counts and minimum pages have to do with the quality of a piece of writing. It baffles me when teachers rather have a 5 page paper with lengthy sentences then a 2/3 page paper that is of quality and meets the standards that were given. That's my new proposed writing construct.