I do consider the entire magical world a cesspool of bigotry, stupidity and corruption. Dumbledore stands out since he was one, if not the leading figure, and therefore responsile for at least some of that.

I do agree that the series does showcase the evil of the magicals very well - if one thinks about it. Immature readers of course might simply eat it all up and go all fanboy. I do guess some maturity is required to really think a world through before playing or writing in it, and not simply accept all words from the original author, even after it has been demonstrated she did not really shine at world building.

 

For not really shining at world building, J.K.R. gave us quite the fascinating world though. Otherwise, I probably wouldn't have read the Potter series.

 

It's very fascinating, but many of the elements were not very integrated with each other. The series suffers a bit from "gimmick of the week", where a thing used to solve the current problem never ever appears again, or never appeared before that, despite being very useful in many other situations. Like unbreakable oaths and veritaserum. Sometimes things are so powerful to break the plot left and right, and one wonders why no one ever uses them - like time turners.

Much of that can be explained away with a bit of planning, but that is not done in the books. No "unbreakable oaths have dire consequences, so no one uses them" or even the cheap "that kind of knowledge is very restricted".