OTOH, I'm not sure why the White House feels compelled to interject itself into this. Rumsfeld is gone. Let history judge, and focus on winning this war.
I see your point, but I think the White House did it because in contrast to some other administrations, there is honor in this one.
They do feel compelled to stick up for Rumsfeld, because he was a hardworking, principled man who spent a great deal of his life in the service of his country.
He could have (and did) make his bones in the corporate world, but chose to serve under various administrations.
The White House did it for the same reason I feel compelled to defend people who have done right by me in life, either giving of their wisdom, time, money or happiness. It is the right and honorable thing to stick up for them when they aren't there.