And out of those (and Giratina is a legendary, so gtfo), how many do you see in PvP? Dusknoir, Rotom, and Spiritomb all have the stats and movesets to do well in a team, but which one of those would you build a team around? They're not sweepers, either.

They get points for having unique type combinations, but when you're dealing with the small number of Ghosts in Pokemon, that distinction gets put into the wash.

Electric/Ground. Grass/Steel. Normal/anythingexceptWaterFlyingPsychic. Hello? There's a good half of the type combinations left. Am I not getting my point across? Are you actually thinking that you can win this argument? How clear do I have to be to express my consternation with this state of affairs like an abomination?