I stopped reading half way though the books, but I had assumed that the SPEW storyline would come back up later and vindicate Hermione. I was very surprised when I heard it never got brought back up. The last word on that story line was that House Elves were a natural slave race and Hermione was wasting her time challenging that. If you read Hermione's cause as just, that's because you have better morals then Rowling.