[Beanamir of Gondor]

I think mayhap they might have been overstating the fact that Isildur the Instigator was extremely important to War of the Ring and the fate of Middlearth. After all, his screwup and loss of the ring led to its disappearance for how many years, and Gollum's finding it, and its passing to Bilbo, and thenceforth, the whole story of the Lord of the Rings. If he hadn't been such a dork in the first place and just destroyed it [mental note, always listen to Elrond!], then the entire story might not have happened. Maybe that's why PJ happened to name him as the last king, because as Saucepan said, his death was sort of linked to the line of Stewards; which is why we hate Isildur as much as Denethor.