Not only did the wizarding world not change, I don't see who is around to change it. Nobody wants change, they want the Sorting Hat so they can ostracize and put down kids from families they don't like, they want wizards in charge of other magical beings and in position to manipulate Muggles and take advantage of them. They want a society based on personal favoritism rather than law. Throughout the series wizards notice the rotten stuff only when it affects them directly, but they are happy to take advantage of the endemic corruption of their society whenever it suits them. So who will fight for an ethical society?

- Oryx