Being a college English graduate who wrote at least 5 papers every semester I can tell you, you can't eloquently place 5 pages of words on 1 or 2 pages, not without leaving ALOT out. If you really want a good "A" paper, you need to have a good introduction and conculsion which take about a page and for every topic you wish to talk about you need AT LEAST half a page to properly get your point across, especially if you have to cite sources. Once a professor asked for me to turn in a 2 page paper with three citations, discussing 3 topics with an introduction and conclusion. That's damn near impossible without writing something pratically in text speak. It's a hell of alot harder to cut down to 2 pages instead of filling five.
Even if you could put it in just a couple of pages, the thing about having a minimum page count is to ensure that the student is spending a true amount of time thinking about the project (if you can just quickly write it down and any size will do, then you don't have to reconsider, add to, move things around and think about what you've written). It also gives student practice writing and honestly, if you don't give students a page count, they'll write a paragraph and turn that in.
Even if you could put it in just a couple of pages, the thing about having a minimum page count is to ensure that the student is spending a true amount of time thinking about the project (if you can just quickly write it down and any size will do, then you don't have to reconsider, add to, move things around and think about what you've written). It also gives student practice writing and honestly, if you don't give students a page count, they'll write a paragraph and turn that in.