Ah, but you never had to submit assignments of code on paper did you? (I do, though not in Perl, not yet. No lecturer knows perl. All of us students are entirely man-page-taught or The-Camel-taught.)
It just makes no sense to submit stuff that way, considering that if it were a complete program on a computer, you just compile and run and you find out if the thing works...

I totally understand about sketching out the idea on paper, I do that too - and my intention was not to cast stones (rocks? pebbles? what is the correct usage?) on that practice. Just a bit of college student spleen being vented, hopefully offending no one. :)