Most modern "forums" have some type of simple rating system: facebook has recently introduced more than just a  that allows users to react to posts; reddit is built on the simple up-vote and down-vote system; stackoverflow relies on upvotes and downvotes to highlight popular topics and questions; along with many, many other examples.

Moodle still does not have this simple functionality as an option. It would add an improved experience for users, allowing them to immediately interact with others without having to type a "good point" or "I agree" or any other low-value comment. It also adds another metric for faculty to see how their students are engaging with the course material.

The current "rating" system is very outdated; I think most people who have used it understand that it is not a good substitute for the suggestions above–maybe this tracker issue could encompass a re-building of the rating system with a more modern UI and could add extended features.