Hmm, seeing how the Dursleys are treating Harry, I wouldn't blame Sirius for giving Dumbles a chewing out, but figuratively and literally. Condemning him to live with them is not going to help the Light. Then, again, I've often wondered about whether Dumbles is in it for the Light or for Albus Dumbledore.
Author's response
To me, Dumbledore is always out for himself, the whole way along. I kinda always thought so, since about the third/fourth book. Even reading the seventh book didn't do much to change my opinion.