It's always morally correct to celebrate the death of evil men.
Moreover, I'm not sure it is right for the president to celebrate this; isn't part of the job of a president to be diplomatic? It's one thing when a nobody like me celebrates the death of someone bad, but I'm not the president, no one expects me to be diplomatic, and generally speaking no one actually cares what I think about anything.
Nice counter though, I walked right into it.
Cheers. That made me laugh!