<p>I’ll try to explain this in the way I’ve experienced it at a large research university.</p>
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<li><p>Professors are often the leaders in their field, and they publish ORIGINAL research to help peers better understand the field. Students, on the other hand, typically write “practice” research; they are writing for a grade. The prof is supposed to grade a student’s work as-is, not a regurgitation of what the prof would like to see. Do you seriously expect a professor to respond positively to a student hounding him for the “answers” in their paper? A casual conversation about where you’d like to take the paper is fine, but to expect him to sit there and read the WHOLE paper and give comments? That’s called grading. GRADING is a big part of how you improve in college. Basically, most profs feel you shouldn’t just weasel your way to a higher mark than you deserve by getting an “practice” evaluation. </p></li>
<li><p>Editors-- Yes, professors often have editors. They check for spelling, grammar, awkward/unclear phrasing. You should NEVER go to a professor asking for help with these things (unless you’re writing in something other than your native language, or if you’re in a basic writing course, IMO). Moreover, they pay people to do this. You’re paying your professor to teach a lecture, not do your busywork. Hire a peer to do that, use a computer program, go to a writing center, or DO IT YOURSELF.</p></li>
</ol>