As long as the killers have been effectively neutralized, I don't consider getting them as being important enough to warrant a long-term manhunt. I'm happy that he's gone, but I'm just not seeing it as a huge moment of victory for the American people or anything.
I agree with your last point, but not the first. Criminals need to be brought to justice, especially those that orchestrate mass murder. It took a long time for a myriad of reasons, but it's done. We should be pissed it took so long, but glad it's finally done.