Paper is Ridiculous

Today in Humanities class I wrote an in-class essay. I was thinking how ridiculous it is to compose essays on paper. The main problem with paper is:

It's hard to go back and edit.

No one naturally writes in one long, organized flow. I think usually the best way to write something is to quickly belt out a first draft, then revise it afterward. It's also useful to be able to make little changes along the way -- it puts you at ease, since you don't have to hesitate and make sure you are getting everything right the first time.

On a computer, revising is the easiest thing in the world. It is as easy as typing. Did you know that if you hold down the control key and then press backspace, delete, or an arrow key, it lets you operate on an entire word of text in one keystroke? Over the course of writing this blog post, I have watched myself take a false start and then instantly backtrack on almost every sentence. That's actually my strategy -- I put down my first idea of how to start the sentence, see how it looks, then go from there.

This computer's powerful editing interface has been around for decades. Why do professors think that paper is still useful as a medium for composing essays in class?