Dumbledore at the end of OotP

On HP4GU there's a thread about Dumbledore's speech at the end of OotP, which I find totally horrifying (the speech, not the thread). It was suggested that everything Dumbledore is saying is essentially to help Harry--he cuts him off talking about Petunia because he (DD) doesn't want him to get off track and doesn't think Petunia's an issue. He talks about Kreacher because he knows Harry might be Kreacher's owner now and needs to prevent Harry from murdering him later. He maybe is trying to show Harry it's okay to be angry at Sirius by talking about Sirius' flaws. Needless to say, I don't agree with this, but for me what Dumbledore is doing in that scene isn't just being a Puppetmaster. ( Really, he's just an ass, imo. )

I got up this morning and went downtown in the pouring rain because there was a big electronic recycling drive where I could bring my old laptop. It's sad how much credit I give myself for this great sacrifice.

ETA: So I was reading the post Aja linked to saying that yes, Pureblood Prejudice is racism. What struck me was the end of the post seemed to also suggest that thinking Pureblood Prejudice was not racism, meant you were a DE apologist. I'm not seeing the leap there. If I argued that anti-Semitism wasn't racism because Jews were not a different race, would I be saying anti-Semitism was right? If I say sexism is not a synonym for racism am I defending sexism? It seems like the word "Prejudice" used in the term "Pureblood Prejudice" is the umbrella term for all these things. Or is just assumed that if you say it's not racism you must be supporting it because racism is the baddest?