I think it depends on the context of "celebration," though. I mean, it's very clear that, in this case, the celebration is of the "good riddance" sort. However, in some cultures (or even some churches) a celebration of death is a celebration that the person who passed away is no longer suffering or in pain.

My dad has told me specifically that he wants a party instead of a funeral. And he wants us to BBQ, put on good music, shoot off fireworks, all that kind of stuff. He figures he'll die from something awful like cancer so to just be happy that he's not struggling against a horrible disease anymore.

So, I wouldn't say that celebrating death is intrinsically wrong; it really is context-dependent.

(But I don't think that this case fits into the "good kind" of celebrating, just to be clear)