Good idea, seems natural as well, since it's already possible to turn off user ratings.
On one of my boards we changed the topic rating to a thumbs up/down version, which greatly increased the usage and the general acceptance of the rating system. The view shows how many percent has voted thumbs up, as long as there are 5 or more voters (configurable).
This worked great for us, but otoh we don't have nearly as flameprone discussions, even though some seem to be bloody serious about their hobby.
