Hahahaha, CK2 is not a complex game. No way. It's easily the most accessible game Paradox has ever released. I'd actually say Civilization IV is vastly more intricate and takes more time to get really good at. Yet look at the awards: IGN Game of the Year '05, IGN Best Strategy Game '05; same with Gamespot; and Baba Yetu won a friggin' Grammy some years ago. Granted, who cares about Grammies. But people still care about Civ IV - you can still find multiplayer games, and there's an active modding community that produced and continues to produce some fantastic stuff (Fall from Heaven, RfC with all its mod-mods, and what not).
Crusader Kings II has spawned quite an array of superb, variegated mods (CK2+, Project Balance, Magnate Lords, Patrum Scuta, the list goes on). It's the most popular game Paradox ever released, based on sales records. It's totally deserving of a nomination at least.
edit: though yeah, the Kotaku guy sounds quite over-eager to me