Theredmission stole my idea

That would be the easiest way to get more ratings entered if it was part of the score submission page. I myself would be more apt to use it.
Instead of "maintenance" though, I'd use the "condition" instead. It's basically the same thing, but even well maintained courses can't account for boneheads who wont repair divots, etc.
I realize that the intention of rating a course is for players to check out courses that they haven't been to before and the ratings allow them to get an idea of what the course is like from a players point of view verses what you see on a website or whatever. I think that ratings should also be based on the condition of the course on the day you play your round verses your overall opinion of the course. I know of many courses that overall I'd rate a "3" or "4" but those same course might be in such poor condition or great condition that day that I'd rate them a 2 or a 5. Not sure if that makes sense or not

but if I was planning on golfing at Course A in the morning, and I saw a recent rating from the day before that was showing it to be in poor shape that week due to the greens being plugged, I would probably try to get on at Course B. Does that make sense? Or maybe I'm just missing the whole point of the rating system.